SHEET METAL ROOFING TECHNIQUES
David P. Rigney
AE 686 Preservation Technology II
Instructor: Phillip Wisley
TABLE OF CONTENTS
MANUFACTURING PROCESSES 2
METALS USED IN SHEET METAL ROOFING 5
LEAD ROOFING 6
COPPER ROOFING 8
ZINC ROOFING AND GALVANIZING 10
TIN AND TIN PLATE 12
IRON AND COATED IRON ROOFING 15
TYPES OF SHEET METAL ROOFING 18
FLAT-LOCKED SEAM ROOF 18
STANDING SEAM ROOF 19
HOLLOW ROLL-JOINTED ROOF 20
RIBBED SEAM ROOF 21
SHEET METAL SHINGLE AND TILE ROOFS 23
PREPARATION FOR SHEET METAL ROOFING 24
SHEET METAL ROOFING TOOLS 25
SLIDE LIST 27
This report will for the most part be concerned with metallic 1
roof coverings in use in Europe and North America from the mid-
eighteenth century to the beginning of the twentieth century. The
area of concern will not be where and when the various types of
metal roofing were used but how and why they were used. In addi-
tion to the aforementioned some emphasis will be placed on the
manufacturing techniques that made metal roofing (primarily sheet-
metal roofing) economically feasible during the period in question.
During the eighteenth and nineteenth centuries great strides 2
were made in the area of manufacturing, especially in the use of
machinery that greatly enhanced man's ability to mold and work
metal. Metal sheets and plates were among the first widely pro-
duced metal products, largely due to the simplicity of the processes
involved in their manufacture once machines had been invented that
were capable of carrying out these processes. Due to this rela-
tively early large scale production of sheet metal a vast array of
architectural products manufactured from this material became
available during the eighteenth and nineteenth centuries. Of these 3
various products only metal roofing lent itself to an architectural
expression of the intrinsic character of sheet metal, namely a rela-
tively light-weight barrier a skin, a sheathing potentially
impenetrable to free water.
The earliest process for forming metal roofing was casting and 4
this process was first applied to lead in the manufacture of metal
roofing probably because of lead's low melting point and the rela- 5
tive ease with which it can be extracted from galena, the most 6
abundant form of lead ore. Lead roofing plates formed in this
manner were used throughout Europe during the middle ages.
The vast majority of the metal roofing manufactured has been
formed by various means of pressing. In the earliest examples of 7
copper roofing the sheets may have been formed manually by ham-
mering and then cut to size. Power hammering is the obvious 8
sequel to the manual process. The process which made sheet metal 9
available in large quantities during the nineteenth century was
the power rolling process. Leonardo da Vinci's sketches for roll-
ing machinery were probably the earliest precedents for the
economically feasible industrial processes developed during the
late eighteenth century for rolling and forming metal products in
large quantities. Esban Hesse in 1532 was among the first to con-
sider the use of the rolling process for forming iron. Even the
treatises of the seventeenth century on the use of rolling-mills-
Zonca (1607), de Caus (1615), Branca (1629) considered the pro-
cess of rolling in context with the softer metals like gold,
silver, copper and lead. The development of these early metal
rolling machines was primarily directed at the production of
metallic stock for coinage. Their use for the production of
sheet metal for roofing would have been totally infeasible from
an economic standpoint.
Christopher Polhem, A Swedish mining engineer, was among the 10
first to implement lolling machinery in the large-scale production
of sheet metal for utilitarian purposes. Polhem's "Political
Testament" of 1746 documents the establishment of his manufactory
at Stjarnsund in 1704 give or take a year. The use of rolling
machinery in Polhem's enterprise was secondary that of the water-
powered hammer forge in spite of the fact that the rolling process
was ten to twenty times as efficient in terms of production. The
Polhem metal works produced a variety of items from several met-
als iron, steel, copper, bronze, tin and lead. Of special
importance in the development of sheet metal roofing materials
was tinned sheet, a major product of Polhem's metal works.
Polhem's contributions to the processes and equipment for the
production of sheet metal were perhaps the most important prior
to 1750. During the 1750's Henry Cort, an Englishman, came to
understand the process of roll-forming metals, especially iron
and steel, better than any of his predecessors. While Cort's
inventions had only a small effect on eighteenth century rolled
metal production, they formed the basis for the vast surge of
production during the nineteenth century. The emphasis of Cort's
inventions was on the manufacture of structural iron shapes. The
advances made in the production of sheet metal were really a side-
effect of Cort's major effort.
Of major importance during the nineteenth century develop-
ments in roll-forming sheet metals was the differentiation of the
hot and cold rolling processes. During the early development of
the rolling processes it was necessary to heat the metal being
formed. The softer metals lead, tin, zinc were of course the
earliest exceptions. During the eighteenth and most of the nine-
teenth century cold rolling was associated primarily with the
finishing process of the harder sheet metals, especially iron and
steel. Many problems were born of the hot-rolling process that 11
have not been fully understood until well into the twentieth
century. Most of these problems arise from changes in the physi-
cal characteristics of metals that take place during the hot-
rolling process. Alteration of crystaline structure and arrange- 12
ment leads to change in hardness and elasticity, and consequently
to proneness to fatigue and fracture. Cold rolling on the other
hand results in a negligible change in physical characteristics
if carried out properly. The process of cold-rolling copper was
apparently well developed during the nineteenth century while
the process was not perfected for iron and steel until the early
After the production of the basic sheet metal an additional 13
step was required for the manufacture of one category of sheet
metal roofing metal shingles and tiles. This process goes back
to concept of the hammer forge for its solution and was available
shortly after the development of machinery for the rolling pro-
cess. The combination of forming dies with a variation of the 14
hammer forge results in the stamping process by which sheet
metal shingles and tiles are produced. While some might disa-
gree, the sheet metal shingle and tile seem to be a major depar-
ture from the architectural expressiveness of the sheet metal
roof and perhaps a mark of decline from the skills required for
the application of the traditional sheet metal roof types.
METALS USED IN SHEET METAL ROOFING
The metals most important in the history of sheet metal roofing
are: lead, copper, tin, zinc and iron. The 1903 edition of The
International Library of Technology makes reference to the use of
bronze in sheet metal shingles, but my research has not revealed any
specific examples of the use of or the manufacture of bronze roofing
materials so discussion of this metal will not be included in this
report. Likewise, steel and aluminum will not be discussed exten-
sively since their use as roofing materials was negligible prior to
the twentieth century. It should be noted that most of the uses of
sheet iron and the means of protecting iron were also applicable to
The qualities that generally determined a metal's suitability
as a roofing are as follows:
1. Malleability is a basic requirement due to the nature
of the manufacturing processes.
2. Ductility or the ability to be drawn thin without
fracturing is always an asset in reducing roofing weight.
3. Tenacity is a major contribution to the versatility with
which a sheet metal roofing may be applied and conse-
quently a determinant in cost of application.
4. Elasticity contributes greatly to any roofing's usefulness
due to the nature of its function. Constant exposure to
solar radiation in cycles with intermitant darkness neces-
sitates the ability to endure continual cycles of expan-
sion and contraction.
5. Resistance to the corrosive influences of moisture, solar
radiation, and atmospheric pollution are also very import-
ant. Unlike the other characteristics lack of resistance
to corrosive influences can be compensated for with a
variety of coatings. This of course is an important fac-
tor in considering the long-term cost of a roofing
Lead was probably the first metal to be used as a roofing 15
material. While certain of its properties require special consi-
deration in its application, lead continues to be useful in roof- 16
ing, especially as a flashing material because of its resistance
to corrosion. The heaviest of the roofing metals, lead is extremely
malleable but lacking in elasticity. Consequently extreme care
must be taken in securing lead roofing with due allowance for ex-
pansion and contraction. This lack of elasticity is in part due 17
to lead's low melting temperature (approx. 6200F), a major factor
in the early availability of lead and in the ease with which it
can be extracted from its ores. This lack of elasticity contri-
butes to a condition called creep if lead roofing is not secured
properly. Roof slope is an abvious consideration when considering
lead as a roofing material. One source considers twenty inches on
center maximum spacing for support of lead roofing and one inch per
foot as the maximum slope to which lead is applicable. Research
beyond this source indicates that the recommended maximum slope is
far to conservative considering Sir Christopher Wren's use of lead 18
on the dome at St. Paul's Cathedral and J. Hardouin-Mansart's uses 19
of lead on the dome of the Church of Invalides in Paris. On the
other hand when lead is used on any roof but one which is nominally
flat twenty inch spacing of supports is inadequate. Twentieth cen-
tury analysis of lead's performance as a roofing material indicates
that sheets should not exceed twenty four square feet in area nor
ten feet in the longest dimension.
Lead's low tensile strength proposes an additional problem in
its attachment as a roofing material. Generally, nailing the lead
sheets directly should be avoided. Lead's lack of tenacity com-
bined with dimensional changes with temperature-fluxuation tends
to cause tearing when lead is nailed. Copper clips or tingles
folded into joints are by far the best solution. There is one
exception to the no-nail rule. When the pitch of a roof exceeds 20
150 lapping may replace constructed drips. In this case two
staggered rows of copper nails spaced three inches may be used to
secure the upper ends of lead sheets.
Lead's low melting point and the general lack of the necessary
technology for milling contributed to the use of cast lead in early
examples of lead roofing. With the introduction of the necessary 21
technology came the use of milled or rolled lead. The pros and cons
of these two forms of sheet lead remains a source of contention.
One point that is generally accepted is the superiority of cast lead
in resisting crackage due to constant exposure to sunlight. On the
other hand casting deficiencies were considered a major problem by
one nineteenth century authority who recommended no less than a
weight of sixty pounds per square foot if cast lead were to be
used for roofing. For milled lead seven pounds per square foot
seems to have been the standard.
In spite of difficulties in proper application a properly in-
stalled lead roof is probably the most enduring of any. The major
problem of corrosion is encountered when lead roofing is used in
conjunction with slate or tile roofing. The acid accumulated in 22
run-off from a lichen covered slate or tile roof is extremely corro-
sive to adjacent areas covered with lead. In situations such as
this copper coursing across the roof's current or at the ridge of
roofing areas covered with slate can control the growth of lichens.
As a roofing material, when weight, durability and aesthetics 23
are all considered, copper is probably the best of the traditional
roofing sheet metals. In sixteenth century France, when English
lead was an occasional substitute for slate roofing, Philibert de
l'Orme recommended copper for its flexible physical characteristics
in his "Inventions for Building Well at Low Cost." As with lead,
cost and availability are the greatest limiting factors in the use
of copper roofing today. Copper is extremely malleable and duc-
tile as well as being possessed of a greater tenacity than any
other common roofing metal except iron. In spite of this quality
clips rather than nailing are always the preferred method of
securing sheet copper roofing. This preference for attachment by
clips results from two of copper's characteristics. Over-working 24
copper sheet, either in its manufacture or by mechanical action
after installment results in a tendency toward fatigue. A rela-
tively large range of dimensional change which occurs during the
normal course of expansion and contraction requires care in
attachment to allow for this movement. To this same end it is
generally recommended that copper roofing not be soldered if the roof
pitch exceeds 150. If copper roofing is to be soldered tinning of 25
the edges to be soldered is recommended.
Copper sheeting is sized by both gauge (thickness) and weight
per square foot. It seems that the traditional designation has been
by weight, sixteen ounces per square foot being the standard of the
nineteenth century and generally excepted today in high grade cold
rolled copper sheet. Sheet size has varied a great deal in the
manufacture of copper sheeting but it seems that 24" X 48", 48" X
72", and 48" X 96" were common sheet sizes. Current standards re-
commend sheet sizes of twenty square feet or less to minimize
drumming, a process that occurs during the expansion and contrac-
tion of large sheet sizes eventually resulting in deterioration
due to fatigue. Overall area can be increased if width is de-
Copper can be formed by both hot and cold rolling processes.
Some sources have indicated a preference for the annealed or hot-
rolled copper sheet possibly because of the ease with which it can
be applied to contoured roof forms. According to research con-
ducted for the Revere Copper and Brass Company, Copper roofing
manufacturer since the mid-nineteenth century, material weight of
32 ounces per square foot is- necessary to achieve adequate strength
and rigidity in hot rolled copper roofing subjected to normal roof-
ing practice. It should be noted that hot-rolled copper does have 26
its appropriate place when used in small sheets (6 sq. ft. or less) 27
in areas where conformity to contour is an asset. Walter Voss
provides a good example of this exception in "Architectural Con- 28
struction", volume one under the sub-title Suburban House. In
this example Ralph Coolidge Henry, Architect, specified 16 ounce
hot-rolled copper for the small domical roof area over a bay window.
A major plus for the use of copper roofing is the pleasing 29
patina it acquires with age. This greenish cast can be of major 31
importance in building design if used in combination with materials
of compatible color and texture.
Zinc Roofing and Galvanizing
Zinc is a late-comer in terms of knowledge as a pure metal 32
because it vaporizes before a temperature high enough to smelt it
from its native ores can be reached. The use of zinc sheet as a
roofing material during the period in question in the United States
is practically nonexistent. This is not the case in England.
There are numerous examples of the use of sheet zinc in England,
the most notable being the sky-lit railway stations of the late
1800's. The Penzance station for the Great Western Railway was a 33
notable example. Numerous other examples are detailed in "Iron 34
Roofs" by Authur T. Walmisely. Apparently availability or lack of
it was a major factor in the tendency towards galvanizing in the
United State's use of zinc.
In terms of physical suitability zinc's qualifications as a
roofing material are excellent. It is nearly as durable as copper
and lead, although it has a tendency towards brittleness. Fluc-
tuation in dimension due to normal expansion and contraction is
not as great a problem with zinc as with copper and lead. Prob-
lems in securing zinc roofing arise from the galvanic action,
destructive to zinc, which occurs when zinc comes in contact with
certain dissimilar metals in the presence of moisture. This
elimates plain iron or copper nails for securing zinc roofing. One
solution is the use of galvanized nails with a tin collar. This
same galvanic action precludes the use of normal half tin-half lead
solders in joining zinc sheet roofing.
Zinc oxidizes rapidly in the presence of moist air, but since
the oxide film acts as a sealer against further deterioration it
is not to be considered a negative characteristic. Underlayments
for all the materials will be discussed later, but it should be
mentioned here that zinc should never be played over bare wood or
any surface that might exude acid, all of which are corrosive to
It was previously noted that zinc's major roll in sheet metal 35
roofing in the United States was as a component of the process of
galvanizing iron and steel. In 1836, I. M. Sorel, a French chemist,
acquired patents on at least five galvanizing processes, the most
important being the hot-dipped process. This process is still used
in cases where a heavy zinc coating is desirable, this including
much of the galvanized roofing in use. The process entails clean- 36
ing the sheet by pickling, a process utilizing acids, then dipping
the sheet in molten zinc. The resulting coating should be uniform
and void of surface defects. 1.2 to 1.5 ounces of zinc per square
foot of surface area (each side) has evolved as a standard for
heavy-duty galvanizing. The galvanizing process forms a layer of 37
zinc-iron alloy between the iron base sheet and the zinc coating.
This intermediate layer is instrumental in the function of galvan-
izing. The function of galvanizing is somewhat more complex than
the concept of coating one metal with another that is less suscep-
table to corrossion. When galvanized iron comes in contact with
moisture or other corrosive influences a voltaic action is set up
between zinc and iron, the zinc coating being slowly sacrificed to
maintain the integrity of the iron.
In addition to hot-dripping, zinc coating may be applied by
electrolysis and Sherardizing, the latter being a dry process uti-
lizing zinc dust to produce a zinc coating on iron. Electro-gal-
vanizing is useful when a thin but uniform coating of zinc is
A number of devices for the automation of the galvanizing pro- 38
cess were invented near the end of the nineteenth century. The
Davies process, the Heathfield process and the Bayliss process.
The Heathfield process was supposedly capable of producing twelve
tons of assorted galvanized sheet, gauges 14 to 30, per ten and
one half hour shift. Apparently the galvanized sheet produced by
this process was finished and ready for use without further treat-
ment. The Bayliss process was similar to processes used in coat-
ing wire, utilizing a series of rollers to direct the sheet metal
through the dipping and finishing steps of galvanizing.
Tin and Tin Plate
Tin is a white metal that could be confused with silver on 39
quick examination by anyone but an expert in metallurgy. Its
earliest use seems to have been as a component of bronze. Tin
is extremely malleable and resistant to fatigue, but lacks elas-
ticity. These characteristics mark tin's use as a foil wrap
prior to its displacement by aluminum. Perhaps tin's greatest
asset as a roofing material is its resistance to corrosion by
atmospheric or acidic influences, far more so than lead, copper
or zinc. Probably due to its relative scarcity I have found no mention
of the use of pure tin sheet as a roofing material. Tin's greatest 40
contribution to sheet metal roofing has been as a coating for iron.
Pure tin and a mixture of tin and lead called terne have been used in
plating iron and steel roofing. Terne plate was probably more common
due to cost. Unlike galvanized iron, tin plate and terne plate re-
quired painting with a metal-based paint to provide adequate protec-
tion for iron roofing. In terne coating the percentage of tin used
varied from ten to fifty percent. The less tin used, the cheaper the
process was. Likewise the quality of the end product diminished
with the decrease in tin content of the coating. In cases where
the quality of a building required the appearance of tin, but dura-
bility was also a major factor it was not uncommon to coat galvan-
ized iron with tin or a high quality terne.
As the use of tin plate became widespread, rigid procedures
were developed for testing the quality of tin plating and the ad-
herence of the plating to the base metal. According to the 1903
edition of the International Library of Technology, "Good tin
plate is determined by the following conditions":
"The sheet should bear cutting into strips of a width
equal to ten times the thickness of the plate, both
across the fiber and in line therewith, without split-
ting. These strips must, while hot, stand the strain
of being bent on a mold, the circumference of which is
equal to four times the width of the strip. The plates
when cool must bear bending on a heading machine to
such an extent as to form a cylinder whose maximum
diameter shall be equal to sixty times the thickness
of the plate."
In addition to these tests a method for detecting lead in tin plate
is described which involves the successive application of acetic
acid and potassium chromate. A resulting yellow coating indicates
the presence of lead, the quantity being indicated by the satura-
tion of the yellow color.
The process of tin plating common in the manufacture of sheet 41
metal roofing is similar to the process of hot-dipped galvanizing.
The same pickling process precedes the actual tinning of the sheet
iron or steel. Sheet iron properly sized and cleaned normally pro-
ceeds through six baths in the tinning process:
1. The tinman's pot, containing grease
2. The tin pot, containing molten tin (5000F)
3. The washing pot, containing molten tin covered with grease
4. The article is brushed free of excess tin and submerged
in a pot of very high quality tin exceeding 99% purity
5. The cold pot, containing tallow just hot enough to
maintain a liquid state
6. The list pot, containing tin for an additional coating
for the edges of the roofing sheets
A crystaline tin surface could be acquired by dipping the still hot
tin plate in dilute nitromuriatic acid, then washing and drying.
This tinning process is that specifically recommended for tinned
roofing by the 1903 edition of The International Library of Technol-
An additional tinning process primarily applicable to the
production of sheet metal shingles is the retinning process. In
some cases shingles were stamp formed from tinned iron. The damage
done to the tin plating by stamping necessitates retinning. Four
steps are normally used in retinning: The first and last steps in-
volve treatment in melted tallow or grease. The second and third
steps involve successive dipping in molten tin. This process re-
stores the integrity of tin plating on stamped articles.
In addition to use as a plating material tin is an important
component of solder. Tin makes up fifty percent of the half and
half solder commonly specified for sheet metal roofing during the
Iron and Coated Iron Roofing
Iron and coated or plated iron roofing materials were probably 42
the most widely used sheet metal roofing materials of the nineteenth
century. Iron is the only sheet metal material that was widely 43
used to combine structural function with the function of roofing
membrane. This quality is primarily applicable to corrugated
sheet iron. For the most part iron roofing was used for utili-
tarian buildings where appearance was not a major consideration.
In buildings of this nature corrugated iron was of great conse-
quence in terms of monetary savings since it could be applied di-
rectly over structural purlins without sheathing or underlayment.
This structural quality is due to its undulating form which acts
structurally in the same manner as a folded plate. This material
was available in black iron and galvanized forms. The undulating
form is the result of an additional step in the rolling process
by which sheet iron is manufactured.
In terms of suitability as a roofing material iron's major 44
drawback is its lack of resistance to corrosion. This may be
overcome to a degree with corrosion resistant coatings discussed
previously, but will still be subject to higher maintenance cost when
long term cost is considered. Iron's rigidity presents a problem
when it is necessary to cover contoured areas. The use of small
sheets can usually deal with the problem of contours. As with all
sheet metal roofing, allowance should be made for expansion and con-
traction, but iron has a degree of advantage in that large sheets
may be used without fear of fatigue related failure. Likewise, iron 45
can be secured more satisfactorily by nailing than metals discussed
up to now because of its superb tenacity.
The black iron most suitable for roofing was of a composition
similar to wrought iron, with a negligible carbon content and
enough silica to provide resistance to rust. Some sources recom-
mended small quantities of copper or manganese.
Iron roofing was generally specified by gauge (thickness) and
during the nineteenth century 26 gauge or .018 inch thickness was
the minimum recommended for roofing applications. The weight for
16 to 26 gauge sheet iron (for general roofing application) ranges
from 3/4 to 2 1/2 pounds per square foot. Sheet size for iron
roofing varied a great deal but 24 inches X 72 inches (for light
weight) and 30 inches X 84 inches (for heavy weight) were common
A common practice was the joining of several sheets of light 46
weight flat iron sheet into fifty foot rolls with single or double
flat-locked cross seams. This came to be known as rolled roofing
and was available with or without galvanized finish.
Twenty-six inches was the most common sheet width for corru- 47
gated iron sheet and the length generally corresponded to that
available in flat iron sheet.
The processes of galvanizing and tinning have been discussed in
previous sections. The variety of sheet sizes and thickness availa-
ble in galvanized sheet correspond with the black iron products.
Specifications for galvanized sheet would of course specify coating
weight in terms of ounces of zinc per square foot of iron surface
The specifications for tin plate are entirely different. Tin
plate was generally available in 14 inches X 20 inches and 20 inches
X 28 inches sized in boxed quantities of 112 plates per box. Coating
specifications indicated a quantity of coating, tin or terne, by
weight per box of 112 sheets of a given size.
A protective coating process for iron, not previously discussed,
and only marginally applicable to the period in question is the
"Robertson Process" patented by H. H. Robertson early in the twentieth
century. It seems probable that some similar process was in use dur-
ing the late nineteenth century. The process involved bonding
asphalt saturated asbestos to annealed iron sheet with an asphaltic
compound. The surface was then subjected to a treatment aimed at
preventing softening due to heat. I have found no evidence regarding
the success or failure of the process. From the description it seems
probable that metal treated by this process would be used only on
utilitarian buildings or perhaps buildings which the roof was hidden
from sight. The sheet treated by this process was apparently
available in sheet sizes and gauges standard to black iron sheet,
both plain and corrugated.
TYPES OF SHEET METAL ROOFING
There are five basic sheet metal roof types that will be discussed
under separate headings (1) flat-locked seam (2) standing seam (3) hol-
low-roll joint (4) ribbed (5) metal shingle. A sixth joint or seam
type often employed in all sheet metal roofing where the pitch is
steep enough is the simple lapped joint. The name explains the tech-
nique. The over-lap ranges from three to eight inches depending on
roof pitch. The minimum of three inches is required to combat capil-
larity. The lapped joint is generally confined to seams running across
the roof's pitch. One exception is in the application of corrugated
sheet iron. In this case a side lap of one corrugation is usually
sufficient for joints running with the pitch of the roof. Minimum
pitch for corrugated roofing is 3 inches per foot. The seams can be
secured by bolts, screws, rivots or nails using lead washers for
sealing the points of attachment.
Flat-Locked Seam Roof
This type of roofing is applicable to all of the roofing materials 48
discussed. It is not recommended for general use unless small sheets
are used due to problems with expansion and contraction. Nineteenth
century sources considered 3/8 inch per foot pitch adequate for the
use of soldered flat-locked seams. Later sources recommend 2 inches
per foot as a minimum pitch for this type of seam. Of the metals
discussed only sheet iron has the tenacity to withstand attachment by
nailing through the roofing sheet in this type of joint. Attachment
by sheet metal cleats or tingles is always preferable. The process
for laying a flat-seamed roof is as follows:
1. The first sheet is played in place and the cleats are
nailed in position
2. Fold the cleats back over the nails
3. Lay the second sheet in position
4. Fold the seam and flatten with mallet (double locked
seam is optional)
5. Solder (optional)
It should be noted that all sheet metal roofing is played from 49
eave to peak, and left to right with the exception of one type of
shingle which will be discussed later. As mentioned in the roof-
laying sequence there is always a choice of double or single locked
joints in flat seaming. The double locked seam is more water tight
when joints are not to be soldered. It is a good rule to stagger
the seams running with the roof's pitch.
Standing Seam Roof
This roofing type is applicable to all the sheet metals discussed 50
and is recommended for the rigidity it gives materials that are
normally lacking in resistance to columnar buckling. This roof type
is applicable to a minimum pitch of two inches per foot although
nineteenth century sources recommended slopes as low as 1/2 inch per
foot. The standing seam runs with the pitch of the roof. Cross
seams should be lapped or flat locked depending on roof pitch. The
steps for application are as follows: 51
1. Lay the first sheet and nail the cleats in position.
2. Fold one end of the cleat over the sheet's up-turned
edge and the other end over the nail heads
3. Lay the second sheet in position
4. Fold the up-turned edge of sheet number two over the
5. Fold and lock seam (double lock optional)
6. Hammer down cross seams
7. Solder cross seams (optional)
Again double locking and soldering of seams is optional. Soldering
is generally not recommended for standing seams. One inch developed
as the standard height for the standing seam. Prior to starting the
roofing application sheet corners should be clipped at 450 and the
sheet edges formed appropriately for the flat cross seams and edges
turned up for the standing seams. The up-turns vary for single and 52
double lock joints. There are a number of variations of the standing
seam that are primarily applicable to flat iron sheet. Two of these 53
involve the placement of a cap-strip over the up-turned edges of the
sheets. In one method the cap is held in place by bolt or rivot.
In the second method the cap is slit at intervals for the penetration
of a split cleat which is turned down to secure the cap. A third 54
variation on the standing seam also used primarily with sheet iron
utilizes roofing sheets with pre-formed standing seams. One type
is secured by cleats folded over the edge of the first sheet then
turned back to hold the adjacent sheet. The second type utilizes 55
triangular blocking for nailers with cross seams secured by cleats.
This latter type of pre-formed standing seam is actually a hybrid
derived from the standing seam and the ribbed seam which will be
discussed later. The major benefit derived from the standing seam
apart from rigidity is a generous allowance for expansion and
Hollow Roll-Jointed Roof
This roof type is a modification of the standing seam roof 56
which is primarily applicable to copper and lead roofing.
technically it could be applied to any of the sheet metals discussed.
But because less coverage per sheet of material is possible with
this roof type it should only be used where special benefit can be
derived, for obvious economic reasons. The application for this
roof type should follow that for the standing seam roof. The up-
turned sheet edges should allow for a standing seam of three to six
inches for copper and six to nine inches for lead. After application
of the roofing is complete, the over-sized standing seams are turned
and molded into hollow rolls. The benefit over standing seam of
this roof type is marginal for copper but lead needs all the added
rigidity that can be achieved. In addition, there is no roof type
that allows for expansion and contraction as well as the hollow
roll-joint type. This roof-type has traditionally been applied to 57
slopes as shallow as 3/8 inch per foot with lead roofing. In these
near flat situations it was necessary to construct step-downs called
drips. The traditional practice of covering large near flat areas 58
with single lead sheets has led to some of the major problems with
lead roofing as detailed under the topic "Lead". As with standing
seam roofing, lapped and flat-locked seams can be used for cross-
seams if roof pitch is adequate.
Ribbed Seam Roof
This roof type can be used with all the sheet metals discussed 59
with the exception of corrugated iron but was normally confined to
copper and tinned roofs. This is the most decorative of sheet
metal roof types, and because of higher cost was generally only
used with the metals considered suitable for buildings of "quality".
Because of the rigidity added by ribbing this roof type has potential
for use with lead. I can only assume that the superiority of hollow
roll-joint roofing in allowance for movement with temperature change
precluded extensive use of ribbed seams with lead.
In England the ribbed roof was used to some extent with sheet
zinc. The decorative quality of ribbed roofing arises from the
relative ease with which crisp, uniform seams could be achieved. In
application of ribbed roofing the ribs may all be placed prior to
the application of the sheet metal, but are normally applied one at
a time as the roofing job progresses to compensate for variations
in sheet preparation. Prior to sheet application the corners should
be clipped at 45 degrees, long edges turned up one inch and the
short edges bent in preparation for flat-locked cross seams either
single or double locked. If roof pitch exceeds three inches per
foot lapped cross seams may be used. Normally ribbed seam roofs
were considered applicable for roof pitch exceeding two inches per
foot. The application of ribbed roofing proceeds as follows: 60
1. First two battens are nailed in place and cleats are
placed and nailed
2. First two sheets are placed
3. Cleats are turned over the upturned edges
4. Partially formed caps are placed over the ribs and
sheet edges and locked in place with the cleats
In an alternative method the sheets are locked in place by the 61
cleats and the cap sprung over the outside of the specially tapered
ribs. In another variation semi-circular ribs are used and the sheet 62
edges merely lapped and nailed. This method is generally applicable
to sheet iron roofing. There is a fourth roofing method that simu- 63
lates ribbed roof. This is called the interlocking pattern. This
method forms a very rigid seam and is less expensive to apply than
ribbed roofing. Ribbed roofing was traditionally known as solid
roll roofing because of its similarity to hollow roll-joint roofing
in appearance. Today it is more commonly known as batten roofing.
Sheet Metal Shingle and Tile Roofs
As mentioned previously sheet metal shingles are stamp-formed 64
from a variety of sheet metals. Of the sheet metal roof types
discussed, shingles are the most economical due to the ease of
application. Sheet metal shingles are applicable to roof pitch
exceeding three inches per foot. Sheet metal shingles come in
many shapes: gothic, square, diamond, polygonal, fish-scale,
simulated roll tile. Special shingles are also manufactured for 65
tapered and cone shaped roof forms. All the sheet metal shingles 66
were provided with inter-locking edges designed to exclude water
if roof pitch is adequate. A flange is provided on one side for
nailing the shingle in place. Most shingles are applied from
eave to ridge and left to right. One specially designed shingle 67
allows application from ridge to eave to allow the removal of
scaffolding as the roofing is placed. Nailing secures one side
of each shingle and adjacent shingles hold the remaining sides.
Pre-formed ridge caps, hip caps and interlocking valley flashing 68
are normally utilized with shingles where shop fabricated inter-
locks, valley, ridge, hip and fascia protectors are more common
with the other sheet metal roofing types.
PREPARATION FOR SHEET METAL ROOFING
The most important prerequisite for the successful application 70
of flat sheet metal roofing is a smooth sturdy surface wood being
the most common during the period in question. Tight fitting board
sheathing played in the direction of the roof's pitch is preferable.
Diagonally played boarding is second best. In twentieth century
application plywood is the best sheathing. For corrugated roofing 71
no underlayment is necessary. As previously mentioned it can be
applied directly to structural purlins or rafters. For copper or
lead roofing it is necessary to cover all knot holes with similar
metal sheet nailed in place with the edges lapped over the nail
heads. All nails for securing sheathing must be counter-sunk. For
copper, lead, tin plate and zinc or galvanized roofing a paper or
felt underlayment should be placed over the sheathing. The under-
layment must be acid free to prevent deterioration of the metal
roofing. Tar or asphalt impregnated papers are generally not
recommended because they interfere with movement due to expansion
and contraction. This is especially true in the case of lead and
copper roofing. This underlayment is optional with iron or steel
roofing, but is recommended due to the corrosive influence of wood
attached to metal resulting from the acid content of wood.
Flashing must be provided on ridges, fascia, eaves, and at
intersections of roof form with walls, chimneys, parapets, and
adjacent roof forms. This flashing can be manufactured from any
of the sheet metals discussed. Black iron is the least appropriate
due to lack of corrosion resistance. Copper and lead are preferred
because of their durability. Special cut nails called wall hooks 72
or wall nails are used to hold flashing in place. As mentioned in 73
the section on shingles, preformed sheet metal finish products are
available for ridge and valley situations. These treatments are
applicable to all sheet metal roofing but have been employed most
where speed and economy are over-riding factors. There are an
endless variety of methods of finishing various parts of sheet
metal roofs that do not lend themselves to verbal description.
SHEET METAL ROOFING TOOLS
The tools used in sheet metal roofing are common to all of the
sheet metal applications:
Shears: These are scissor-like tools used in cutting metal 74
sheet. The blade shape varies according to the type of cut.
Stakes: These are tools which come in a variety of sizes 75
and shapes and are used for a multitude of forming procedures.
This tool is designed for bench use and has an extension for
attachment to a work bench.
Mallets and hammers: The cross-peen hammer is used extensively 76
for forming procedures and for placing sheets for flat-locked
seams. The wooden mallet is used to flatten seams to avoid
rupturing the metal surface.
In addition to the above there are a multitude of eighteenth and 77
nineteenth century inventions for folding and locking sheet metal
seams, for making long straight cuts in sheet metal and for bending
sheet metal. The soldering iron is an additional tool used by the 79
sheet metal roofer. A few of the sheet metal worker's tools are
included in the accompanying appendix.
1. SHEETMETAL APPLICATION
Practices, pp. 6-19.
AND SPECIFICATION, Modern Sheet Copper
2. IRON ROOFING PRODUCT MARSHALL LEFFERTS AND BROTHERS, Architectural
3. ROOFING COST EVALUATION, Construction Estimates and Costs, pp. 294-301.
4. CARE AND REPAIR OF COPPER AND LEAD ROOFING, The Care and Repair of
Old Buildings, pp. 96-104.
5. MISCELLANEOUS INFORMATION ON METAL ROOFING, "Early Roofing Materials",
APT Bulletin, Vol. II, Nos 1 and 2, 1970, pp. 28-29, 37-38, 50-51.
6. APPROPRIATE ROOF COVERINGS, Elementary Principles of Carpentry, p. 89.
7. SHEET METAL TOOLS, Sheet Metal Workers Manual, pp. 126-143.
1:-Ei 3 Bp T 1
Standing seam roofing, roll method PLATE NO. 1
The roll method of applying standing seam copper roof-
ing originated with the terne plate steel roofs that were
popular some years ago. These roofs had locked and
soldered cross seams and were painted after being in-
stalled. They were applied on roof decks having a slope
ranging from 2" to 6" per ft.
The roll method of standing seam roofing has been used
successfully with 10 oz. Economy Copper Roofing fur-
nished in strips 16" wide by 72" long. The 10 oz. mate-
rial lends itself particularly well to this method of con-
struction because the gage is practically the same as
that of terne steel roofing, and, the ductility of copper
and its excellent forming qualities are advantages which
mean savings in energy and time.
16-oz. copper of roofing temper can also be applied by
the roll method, but the work is somewhat harder, there-
fore, the pan method of making standing seam roofs is
preferred when 16-oz. copper is used.
The drawing shows the strips of copper joined together
endwise with 3/4" clinch locks without solder. In order
to keep the strips in alignment, indentations are made
with a center punch at both edges of the cross seams.
The strips which are loosely wound into rolls for easy
handling are unrolled on the roof deck where the
edges are turned up with edging tongs. One edge
Q, is 1/4" higher than the other to form the first fold of
the double lock standing seams. The seams are then
completed with the seaming tongs or "kickers" except
at the ridge and the eave where the work is done with
hand seamers and regular sheet metal tools. The up-
standing edges of the roof pans are 1" and 11/4" for a
finished standing seam 3/4" high.
Standing Seam Copper Roofing may be applied by the
Roll Method using strips of sheet copper of the proper
width. These strips are to be joined together endwise
by means of a 3/4" clinch lock joint, temporarily kept
in alignment by indenting the metal at the folds of the
lock with a center punch. The strips so assembled shall
extend from ridge to eave or to the valley. The edges
are to be turned up with roofing tongs as shown on the
drawing, to form a double lock standing seam. The
smaller upstanding edge of the formed strip is to be
anchored to the roof deck at 12" intervals with 11/2" x 3"
copper cleats. The finish at the ridge and at the eave
and valley is to be as shown in detail.
The copper is to be 10-oz. Economy Copper Roofing
applied in sheets 16" x 72" having a slight temper.
Alternate: The copper shall be of 16-oz. gage in
sheets 20" x 96".
J -~ -llleL1~91~LPPsBI"~lB~P~-~'~ r_ 1_1
PLATE NO. 1
Standing seam roofing, roll method
ANACONDA SHEET COPPER
made by The American Brass Company
made by The American Brass Company
Standing seam roofing, pan method PLATE NO. 2
In the early days of standing seam roofing it was cus-
tomary to assemble the strips of copper endwise reach-
ing from ridge to eave, then to form upstanding edges
on these long strips with the aid of edging tongs. The
channel shaped roofing strips were then moved into
position, fastened to the roof deck, and the double lock
standing seams were made with hand seamers or with
special double seaming tongs known as "kickers." Some-
time later when the bending brake came into being it
was found that a better job could be done by forming
8 ft. lengths of sheet copper into roofing pans with
the help of that new device. In this procedure there is.
the advantage of forming the pans quite completely in
the shop, making the work of installing on the roof
very simple and relatively easy. It is only necessary
to close the last two bends of the double lock standing
seams with hand tools on the roof.
Standing seam copper roofing by the pan method is
generally made of 16-oz. copper, the sheets measuring
20" wide by 96" long. The ends of the sheets are folded
with 3/4" reverse bends so as to form a clinch lock
when assembled end to end. The edges are then formed
so as to finish with either a 3/4" or 1" standing seam.
The pan method has been used with 10-oz. Economy
Copper Roofing consisting of sheets 16" wide by 72"
long, intended principally for residential work. The
technique of forming and applying is exactly the same
as for 16-oz. copper. Economy Copper Roofing lends
00 itself well to a 3/4" high seam for steep roofs. It is more
likely to remain straight and true, and produces a very
attractive architectural shadow line.
The drawing illustrates a suggested method of applying
copper roofing on a house by the pan method. The de-
tails show a 3/4" common clinch lock joint forming the
cross seams. The clinch lock at the junction of the roof
pans and valley is made up of 3/4" and 11/2" return
bends thereby offering greater protection at the valley
where there is a heavy flow of water. The valley has a
comb or ridge in the center to interrupt the onrush of
water from a wider slope, and to arrest and steady the
flow at the center of the valley. This feature is only
necessary where the lengths of slopes draining into the
valley are unequal.
Standing Seam Copper Roofing by the Pan Method shall
consist of 16-oz. sheet copper measuring 20" x 96"
formed into roof pans in the shop with a mechanical
bending brake. These pans are to have reverse bends
at the upper and lower ends to interlock with the ad-
joining metal. The longitudinal bends for the standing
seams are to be formed on the brake, except for closing
of the last two folds of the seams which is to be done
on the roof. These pans are to be anchored to the roof
deck at 12" spacings with copper cleats having 2 nails
in each cleat. A tab on the cleat shall be bent back over
the nail heads to prevent chafing. The finish at the
ridge, eave and valley is to be as shown on the drawing.
PLATE NO. 2
Standing seam roofing, pan method
ANACONDA SHEET COPPER
made by The American Brass Company
made by The American Brass Company
Standing seam roofing, pan forming details PLATE NO. 3
This drawing shows the procedure in forming roof pans.
Starting with a blank or plain sheet of copper, the cor-
ners are notched to cut away some of the metal that is
not needed to make a weather-tight construction, and
which would be troublesome in making the seams. This
operation is followed by making the reverse bends at
the top and bottom edges of the sheet, then turning up
the sides with their additional small bends, thus form-
ing pans that can easily be interlocked on the roof.
There the standing seams are completed by simply clos-
ing the last two bends with regular hand tools.
Many standing seam copper roofs have finished seams
3/4" high like the copper roof on Christ Church in Phila-
delphia. This is the oldest metal roof in existence in the
United States, well in its third century of service. In re-
cent years, and particularly for roofs with a low pitch,
architects have in many instances specified seams 1"
high. Whether the seams are to be 1" high or 3/4" high
is largely a matter of taste, and is influenced by design,
climatic conditions and pitch of roof.
The end locks of the roof pans as shown will form
a simple single lock clinch joint. For roofs that have a
pitch of less than 6" per ft., it is sometimes considered
good judgment to make the reverse bend at the top of
the pan 11/2" wide instead of 3/4" so as to offer greater
protection at the cross joints and to cushion the blasts
S of wind that could possibly force rain water into the
0 joints. In that case it might also be considered wise to
finish the standing seam 1" high. The 1" seam is pre-
ferred on slopes having a pitch of less than 3" per ft.,
in which case the cross seams should be filled with white
lead paste or caulking compound to prevent the infiltra-
tion of wind-driven rain or back-up water from ice or
slushy snow. If blind soldering of cross joints is resorted
to, copper of cornice temper must be used.
Standing Seam Copper Roofing-Pan Forming Details: The
roofing pans shall be made from a sheet or blank of cop-
per of 16-oz. gage, measuring 20"x96". This blank is to
be notched at the corners, as shown on the drawing, to
remove the excess metal that would otherwise fold into
the double lock standing seam, making an unnecessarily
bulky joint. This is followed by making reverse bends
at the end of the sheet to interlock with the adjoining
work. The sides of the roof pans are then formed on
a standard bending brake, allowing a very slight taper
from end to end so as to permit easy interlocking of the
successive pans. These shop-made pans are completed
on the brake, except for 'closing the last two folds of
the double lock standing seams which is done on the
roof. The upstanding edges are to be of a height that
will make a finished seam 3/4" or 1" high, as directed.
Alternate: The roofing pans shall be made from 10-oz.
Economy Copper Roofing stock measuring 16" x 72".
-~-~~ ----1`-"-~ ~`-~1`*~`C11~311CI~LC~~JLllsCL~-II~II& ~ "-FPI ii
PLATE NO. 3
Standing seam roofing, pan forming details
ANACONDA SHEET COPPER
made by The American Brass Company
Batten seam roofing PLATE NO. 4
The batten seam is the most popular type of copper
roofing. It is commonly used for monumental buildings,
and on structures where a long-lasting roof covering is
required. This kind of roof provides weather-tight con-
struction without the use of solder, and it enhances the
beauty of the building not only by its color, but also by
a proper proportion or spacing of the battens. In climates
where there is much snow, such roofs are usually de-
signed to be quite steep in order to shed the snow free-
ly, thus avoiding heavy snow loads, as well as back-up
troubles that may develop on uninsulated roofs with
overhangs. Some of the finest batten seam copper roofs
in Canada are of steep Norman design with 2" x 1" bat-
tens. In a more temperate climate the roofs are gener-
ally not so steep, and 3" x 2" or 2" x 11/" battens are in
order because of the likelihood of occasional deep slush
or thin crusts of ice or snow which cause diversion or
damming of the water in its course down the surface
of the roof.
This drawing shows a rectangular batten, with the cop-
per roof pans laid loosely between the battens allowing
a 1/16" clearance at the base of the batten on each
side. In making up the cross joints, the leading edge of
the laid pan is raised above the top of the batten and
the sides are flared outward so that the successive pan,
with its bottom edge also flared, can be interlocked
and the two worked back into place between the bat-
tens with a broad-faced tool. The cross joints are ordi-
narily left dry, without solder, and closed lightly with
a block of wood and a mallet. For slopes that are less
than 4" per ft., the cross joints should be filled with
white lead paste or a suitable caulking compound be-
fore malleting. Blind soldering may be resorted to, but
in that case the copper must be cornice temper.
Ih For best appearance, batten seam roofing employs sheets
of copper that are 24" wide by 96" long, usually of 16-
oz. or 20-oz. gage. The cross joints are ordinarily of
the single lock type, having a 3/4" clinch lock. The
copper of the roof is always secured with copper cleats,
as illustrated, to allow for expansion and contraction.
Where the roof pans on the slopes adjoin the valleys,
or at an apron at the eaves, extra protection may be
had by forming a clinch lock with a 1 2" turn-back on
the underlying sheet and a 3/4" reverse bend at the
bottom edge of the roof pans, as shown in detail. Where
the roof pans butt against the ridge cap, the corners
of the pans are folded in a manner as shown, which
does not require cutting or soldering.
Batten Seam Roofing shall be installed in accordance
with recognized best practice in the trade, using 16-oz.
sheet copper of cornice temper 24" x 96". The roof
pans are to be formed on a standard bending brake,
and there is to be no notching or soldering of the metal
if it can be avoided. All joints are to be made with a
simple clinch lock, closed gently with a block of wood
and a mallet. The clinch lock at the batten covers is to
be 1/2", at the cross seams and at the eave, 3/4", and
at the valleys and apron, 1 /2", as shown in detail. The
ridge pole and the batten ends, as well as any other
parts of the roof construction, are to be covered with
copper to make a complete installation.
Alternate: . . using 16-oz. sheet copper of roofing
temper 24" x 96". It is imperative that the roof pans
have an absolute clearance of at least 1/8" between the
battens; also, under no circumstances shall the copper
work be fastened by direct nailing through the sheet,
nor is solder to be used with copper of roofing temper.
PLATE NO. 4
Batten seam roofing
ANACONDA SHEET COPPER
made by The American Brass Company
Covered dome PLATE NO. 5
The dome was an important element of design in the
architecture of old, and continues to be important in the
architecture of today. It is a basic engineering form.
Its beauty of line and inherent strength make the dome
especially suitable and economical in covering large
areas with wide spans where columns or posts would
Regardless of the architectural shape or proportions of
the dome, there are certain basic principles of sheet
metal work that must be observed if the copper covering
is to give the best possible service. In general, any por-
tion of the dome with a slope of less than 3" per ft.
should be roofed with flat lock soldered seam roofing.
The portion of the dome with a slope greater than 3"
per ft. can be covered with 16-oz. copper applied either
by the standing seam or batten seam method of con-
struction. Dry lock clinch joints may even be used on
steep domes with a minimum pitch of 12" per ft., pro-
vided the horizontal seams are not more than 24" apart
and the vertical seams are filled with caulking com-
pound or white lead paste.
This drawing shows a type of copper dome that may be
used either in classic or modern design. It is character-
ized by bold, horizontal shadow lines and by radial stri-
ations produced by small battens formed of 1/2" x 11/2"
inverted bronze channels. In general, the major portion
of the roof is of regular batten seam construction. For
this purpose, sheets of 16-oz. copper of cornice temper,
20" wide by 96" long, or 20-oz. copper of cornice tem-
per, 24" wide by 96" long, are particularly suitable. For
the crown, flat lock soldered seam construction with
roofing squares 16" x 18" of 20-oz. copper of cornice
temper with 11/2" pretinned edges should be specified.
The built-in gutter and the expansion joints, as shown,
should be of a gage ranging from 20-oz. to 32-oz.
. copper of cornice temper, depending upon the breadth
and size of the gutter. The inner and outer edge must
be designed with freedom for movement, and the ex-
pansion joints should not be over 40' apart.
Dome Roofing shall consist of sheets of 16-oz. copper
of cornice temper in sizes not exceeding 24" x 96". The
battens are to be formed of inverted bronze channels
of a size and gage specified on the drawings. The bat-
tens are to be secured to the roof deck at intervals of
not over 12" with No. 12 bronze wood screws, or No. 12
machine screws set into brass and lead expansion shields
for fireproof construction. The cleats of 16-oz. copper
which hold down the roof pans are to pass under the
battens in stirrup fashion, at 12" spacings.
The roof pans are to be accurately formed on a bending
brake so as to fit properly between the battens, with a
1/16" clearance between the bottom of the batten and
the heel of the roof pan. The batten cover is to be of
16-oz. copper forming a clinch lock with the upstanding
legs of the roof pans. All the work in the standing
seam portion of the dome is to be in accordance with
the drawings and details, and without solder. The
crown of the dome, where the pitch is less than 3" per
ft., is to be roofed by the flat lock solder seam method
of construction, using 16" x 18" roofing squares of 20-oz.
copper of cornice temper. The corners of these squares
are to be snipped on a 45" angle, and the edges of the
squares are to be tinned 11/2" wide. These roofing
squares are to be laid with 3/4" clinch locks, soaked
full with 50/50 lead-tin solder using cut muriatic acid
as a flux. The roofing squares are to be secured to the
roof deck with five 11/2" to 3" copper cleats in each of
the roofing squares.
PLATE NO. 5
ANACONDA SHEET COPPER
made by The American Brass Company
Flat lock soldered seam roofing PLATE NO. 6
Except for vertical surfaces, church spires and the steep
portion of domes, flat seam roofing must necessarily be
soldered so as to be weather-tight and water-tight. Un-
like other types of copper roofing in which the sheets of
copper can expand and contract freely because of the
dry lock joints, as with standing seams or batten seams,
this kind of roofing with soldered joints becomes, in
effect, a single sheet of copper over the entire roof or
roof panel area. Therefore, unless copper of a proper
thickness is used and suitable provision is made to allow
for expansion, waves or buckles will form in the roofing
squares in hot, sunny weather. In turn, during cold
weather the metal will become stressed due to contrac-
tion, the force becoming increasingly greater outward
from the center of the panel or roof area.
It has been learned from experience that long-lasting
construction will result if the roof is divided into rec-
tangles about 40' square, thereby creating a number of
small roof areas isolated from one another by expan-
sion battens. This drawing suggests such small roof
areas surrounded by expansion battens with expansible
intersections (1) so designed that all the copper can con-
tract a reasonable amount in cold weather without ex-
cessively stressing the metal. For roofs that are to
be sprayed or flooded with water, all joints must be
At the edge of the roof or at vertical extensions at para-
pet walls, the battens can be beveled on the top surface
and the roofing copper or batten cover can be folded
without cutting the metal, in a manner as shown on the
drawing (2). Where the flat seam roofing adjoins a wall,
it is finished with a base flashing of cold rolled copper
with soldered cross seams, extending up behind a loose
counter flashing in the usual way (3). Where the roof
S extends over a cornice, it can be finished with an edging
a. strip forming a drip edge at the crown mould as shown
(4). For an overhang or sunshade, as in contemporary
design, the roofing can finish at a point slightly back
from the edge, with a canted edging strip (5).
For flat lock soldered seam roofing, as well as for all
other soldered work, the copper must be of cornice tem-
per of a suitable gage. Roofing squares of 20-oz. cop-
per measuring 16" x 18" are the most economical.
The expansion battens, the edging strips and the base
flashing should likewise be of 20-oz. copper of cornice
temper. Generally, all soldered joints are to be pre-
tinned, clinch locked 3/4" and filled with regular 50/50
Flat Lock Soldered Seam Roofing shall consist of 20-oz.
copper roofing squares, measuring 16" x 18", with sold-
ered clinch lock joints. The copper is to be of cornice
temper. The corners of the roofing squares are to be
clipped to facilitate making reverse bends for a 3/4"
clinch lock, and the edges are to be tinned 11/2" deep
by dipping the squares in a bath of molten tin. The
roofing squares are to be laid in rows parallel to their
long dimension, braking joints in the other direction.
Each square is to be fastened to the roof deck with 5
cleats of 16-oz. copper. The joints are to be closed with
a block of wood and mallet, and soaked full with 50/50
Expansion battens and expansible intersections are to
be made of 20-oz. copper of cornice temper and in ac-
cordance with the drawings. The edges of the copper at
the joints are to be cleaned free of oxide, pretinned and
PLATE NO. 6
Flat lock soldered seam roofing
ANACONDA SHEET COPPER
made by The American Brass Company
PLATE NO. 7
made by The American Brass Company
MARSHALL LEFFERTS & BROTHER, 1854
When Marshall Lefferts died in 1876, he was honored chiefly for his service as a colonel with the
Seventh Regiment of New York and little mention was made of his business career. He was, how-
ever, a leader in the American manufacture of galvanized iron and in the building of telegraph lines
in this country.
Born in 1821, Lefferts received a public school education and later became engaged in
engineering work in surveying Brooklyn. Shortly thereafter he entered the New York importing
house of Morewood & Co. and soon became a partner. This firm was engaged extensively in import-
ing zinc wire and other products used in the erection of telegraph lines. His experience in this
firm led him to establish his own business under the name of Marshall Lefferts in 1852. One of his
first activities during that year was to publish a catalog much like the 1854 one reproduced here,
although the 1852 edition was not illustrated.
About this time Edmund Morewood was engaged in experiments with the manufacture
of galvanized iron in England, being granted patents between 1841 and 1852, and it would not be
surprising that he dealt with the New York firms. One of Morewood's patents was for coating iron
with tin and zinc and Lefferts did carry "galvanized tinned iron" when he first established his firm.
Edmund Morewood's patent, howe ier, specified that the iron should be coated first with tin and then
zinc, the reverse of Sorel's process mentioned in the introduction, but both techniques were de-
signed to give the finished product a shinier a, arance. Furthermore, Lefferts makes reference in
Plate 3 of the 1854 catalog to "Morwood's Book," and, as a footnote, one of his five sons was named
George Morewood Lefferts.
In 1849 Lefferts also became president of the New York, New England and New York
State Telegraph Company and served until about 1860 when it was consolidated with other lines.
Meanwhile in 1853 his brother, John A. Lefferts, entered the galvanizing business, and the com-
pany became known as Marshall Lefferts and Brother. This firm continued in business until 1861,
not only handling imported products but also engaging in manufacture. In 1862 Marshall Lefferts
briefly operated the business alone.
In 1861 he had become electrical engineer of the newly formed American Telegraph
Company, which he turned into what was called "the most complete, efficient, and thoroughly or-
ganized telegraphic system in the world." During 1861- 63 Lefferts served in the Civil War, and
from 1869 until his death he was president of the Gold and Stock Telegraph Company. He summa-
rized his interests in these fields thus in 1852: "We have certainly seen, within the last half century,
the most surprising changes in the condition of human affairs, brought about by the scientific ap-
plication of established principles to practical uses. . The progress of science has in nothing
been more marked than in its use of electro-galvanism, to form such a combination of metals which
shall completely neutralise this tendency of iron to rust."
Lefferts' entrance into the galvanized iron business coincided with the discovery and
mining of zinc in this country. Mines had been opened in northern New Jersey in 1848 and in east-
ern Pennsylvania in 1853, but it was not until about 1860 that spelter, the metallic zinc needed for
galvanizing, was successfully made in the United States from domestic zinc ores. Consequently
the spelter initially used by Lefferts undoubtedly was imported from Europe, but in his work with
the telegraph, he probably used American zinc, which was greatly preferred to the European.
Meanwhile in 1863 John C. Lefferts engaged in the galvanizing business, which became
John C. Lefferts & Co. in 1865-66 when George M. Lefferts, Marshall Lefferts' son, joined the firm.
In 1867 another son, Marshall Lefferts, Jr., replaced his brother in the company, and in 1873 he took
over the business, which continued as Marshall Lefferts and Co. until 1909.
PERFECTLY RUST PROOF,
THE CHKEAPVT AND MOST
ROOFS, GUTTERS, SPOUTS, LEADERS, BATHING-TUBS,
TELEGRAPHIC WIRES, SHIPS' BOLTS, SPIKES,
FENCES, LIGHTNING RODS, ETC.
IMPORTED AND MANUFACTURED BY
MARSHALL LEFFERTS & BROTHER,
70 & 71 BROAD STREET.
WM. C. BRYANT A CO., PRINTERS, 41 NASSAU ST., COR. LIBERTY.
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Plate No. 6.
KLTP JOINT hALF ROUND GUTTER.
The wires d d fit into the bead a n, and c fits into the socket
b, which is to be filled with red or white lead. No soldering is
The brackets for supporting the gutter should be galvanized.
Fig. 15--Stamped Eves' Gutter.
1hFig. 14-Ridge Cap.
Plate No. 7.
STYLES OF GUTTERS MADE OF GALVANIZED IRON.
?oak A .9
In both 1852 and 1854 Lefferts offered flat as well as corrugated galvanized roofing
sheets. Flat iron sheets (not galvanized) had been rolled at the end of the eighteenth century and used
in America by the opening of the nineteenth century. Corrugating had been invented in England
about 1828, and within the next five years corrugated sheets had been used for the roofing of London
docks. J. C. Loudon's Encyclopedia of Cottage, Farm and Villa Architecture, 1833, considered cor-
rugated iron particularly appropriate for larger cottages, "smithies, carpenters' shops, and all man-
ner of sheds," as well as for portable houses, but warned that "wherever such houses may be erected,
they must be covered with ivy, or some other evergreen creeper, to moderate the effect of changes
in the exterior temperature."
In 1852 Lefferts outlined the extent to which galvanized plates were then being used and
commented upon their advantages over other common roofing materials:
In this country attention has been chiefly directed to the galvanized tinned iron for
roofing, guttering and spouting, and for these purposes the sales are now very large. In our own
and neighboring cities, most of the finest buildings are covered with this material; and for ref-
erence we would mention the Merchants' Exchange, New York Post Office, Brooklyn City Hall,
Grace Church, the magnificent store of A. T. Stewart & Co., Broadway-all the stores of the
Atlantic Dock Co., besides a great number of splendid private residences . roofs and other
works so protected will be found in nearly every principal city in the Union.
The peculiar properties and advantages of the patent galvanized tinned plates consist
in their great strength and durability-in their malleability, and especially in the fact that they
are PROOF AGAINST RUST-costing less than half as much as copper, and possessing all the
good qualities of that expensive metal. They will remain an indefinite length of time unimpaired
by the weather, as well upon the seaboard as in the interior; contracting and expanding very
slightly from changes of temperature, they will not crack or leak like zinc or tin. They never re-
quire paint, like the ordinary tinned plate, and consequently are cooler in summer.
Testimonial letters appearing in the catalogs provide information on some of the earliest
uses of galvanized iron. One of the first was in the roof and leaders of the Merchants' Exchange in
New York, whose architect, Owen G. Warren, remarked in 1847 that he had been "in the habit of
noticing them" since about 1839. The chairman of the Building Committee for the Merchant's Ex-
change reported in 1842 that he was acquainted with galvanized iron which had been installed in
other buildings for three years. Peter Naylor, a leading New York City metal roofer, wrote to Lef-
ferts in April, 1852, regarding galvanized iron that "I have now been in the habit of using it con-
stantly for the last twelve years, and for seven years have employed it almost exclusively in all
my work." And it was apparently sufficiently well known and widely distributed for Edward Shaw
to recommend in 1843 in the pattern book Rural Architecture that roofs "be covered with galvanized
iron or tin." These examples all evidently refer to the use of flat plates.
Since corrugating iron plates made them much stiffer and stronger, roof framing
could be lightened when a lighter gauge sheet was employed or eliminated when the sheet was
curved. In 1852 Lefferts wrote that "Corrugated Galvanized Iron is now being largely used, and
possesses advantages which we have not heretofore enjoyed in roofing.-The form of corrugating
gives so much strength to the sheet, that the roof requires no boarding-the ends of the sheets rest-
ing simply upon rafters" and illustrated this procedure in the 1854 catalog. Corrugated sheets were
widely used by both British and American manufacturers (including Peter Naylor) in making pre-
fabricated portable houses that were shipped to California during the Gold Rush. Lefferts pointed
out another application to prospective customers in 1852:
There is now being constructed under orders of the United States Government, CORRUGATED
GALVANIZED IRON HOUSES, to be stationed on our Atlantic coast, in which is kept the life-
boat, and all life-saving apparatus, and which in case of shipwreck affords immediate and com-
294 CONSTRUCTION ESTIMATES AND COSTS
In addition to the types of composition roofing mentioned,
there are many special types prepared and applied by various
manufacturers and dealers.
Diagrams 10-1 and 10-3 may be used for estimating the costs
Super square of composition roofing materials.
12. Canvas Roofing.-Canvas roofing of two- or three-ply
construction may come in rolls 29 to 72 in. in width, and 100 yd.
in length. The weight may vary from about 12 to 24 oz. per
square yard. The canvas roofing should be laid in paint on a
smooth surface and the finished roof given one or two coats of
paint. The canvas should be fastened by copper or galvanized-
steel or iron tacks about % to % in. long and spaced about 1 in.
or less apart. From 8 to 12 per cent should be allowed for laps
and waste in cutting and fitting. Flashings may be formed by
extending the canvas 6 to 8 in. up the sides of the walls. This
extra material must be allowed for. The canvas may cost
$30 to $80 per square, according to weight and number of plys.
The cost of the paint is additional.
The materials estimate for a canvas roof should include
canvas, tacks, and paint.
13. Metal Roofing.-Metal roofing is usually rolled open-
hearth steel roofing of about 22 to 29 U. S. gage and may be plain
(black), painted, tinned, or galvanized. Rust-resisting steel
alloys (usually copper bearing) are asio available. Other metals,
especially copper, are also used. Sheathing or roofing paper may
or may not be placed under metal roofing.
Flat or Sheet Roofing.-This roofing comes in sheets. Material
may be sheet steel, tin plated, with the underside painted, or
copper. The sizes of tinned steel sheets are 14 by 20 in. or
20 by 28 in., the larger sizes being preferred. Common thick-
nesses or weights are U. S. gage 26, 28, and 29. Weights per
square foot for these gages are a little more than the correspond-
ing. weights of black finish flat sheets given in Table 10-5.
This material may come in boxes of 112 sheets of the 14- by 20-
in. size, 56 sheets of the 20- by 28-in. size, or in boxes containing
100 lb. of material. This material may be laid with standing
seams or laid flat and soldered.
For a standing-seam roof, 32 sheets of the 20- by 28-in. size
or 68 sheets of the 14- by 20-in. size are required per square for
covering and laps for seams.
ROOFING AND FLASHING 295
The materials needed for a flat soldered-seam roof are given in
Table 10-3. The table gives the number of sheets required,
including laps. From 4 to 8 per cent should be added to tabular
S values for waste of cutting and fitting.
TABLE 10-3.-FLAT SOLDERED-SEAM ROOF. MATERIALS PER SQUARE
Material Using 14- by 20- Using 20- by 28-
in. sheets in. sheets
Sheets, number........ 62 29
Solder, pounds......... 7-9 4-6
Nails, pounds.......... 3-5 3-4
Rosin, pounds...... .. 1 1
Charcoal, pounds...... 2 2
This roofing material may cost $12 to $20 per square for stand-
ing seams, and $16 to $25 per square for flat soldered seams,
including solder and other materials. The material may be
priced per sheet, per box, per pound, or per 100 Ib., with gage
and other details being given. At the present time, tin-plated
steel roofing may cost $5.50 to $7 per 100 lb. at the job.
Copper roofing sheets come in varying sizes and weights.
Common weights are 14 or 16 oz. per square foot. The roof
may be laid flat or with standing seams. Copper roofing may
be laid over roofing paper or light-weight roofing felt. Copper
or bronze nails should be used if nailing is required. About 5 per
cent should be allowed for waste in addition to laps. Copper
roofing may cost $25 to $50 per square.
Crimped and Corrugated Roofing.-Standard sheets of crimped
and corrugated-steel roofing are available in rust-resisting alloy
steel (copper bearing), open-hearth steel, black (unpainted mill)
finish, painted, or galvanized finish. Common gages are 22, 24,
26, 28, and 29 U.S. Standard lengths are 5 to 12 ft., with 1-ft.
variations. Standard widths are 26 or 27.5 in., giving a net
width of 24 in., allowing for side laps of 2 or 3.5 in. These
types of steel roofing are usually priced per 100 lb. with various
extras for quantities and gages.
The estimator should consult the material dealer for prices
(base prices and extras) in effect at the time the estimate is made.
Prices may be f.o.b. mill, f.o.b. nearest railway station, or
delivered at job. At the present time, approximate prices per
296 CONSTRUCTION ESTIMIATES AND COSTS
100 lb. delivered at the job may range from $3.50 to 85 for black
(mill) finish and from $4 to $6 for galvanized.
Maiy dealers price crimped, and corrugated-steel roofing by
the sheet, with gage, width, length, finish, and other details
given; or by the lineal foot for standard lengths with gage, width,
finish, and other details given. This method of pricing is popular
in many districts where the roofing is used for barns and other
wooden-frame buildings. Prices per lineal foot may range from
about $0.07 to $0.12 for 26- or 27.5-in. painted material for
26 and 28 gages, and from about $0.10 to $0.20 for galvanized
material of 26, 28, and 29 gages.
Barbed lead-headed roofing nails about 1.75 in. long should be
used for fastening crimped or corrugated-steel roofing to wooden
sheathing. From 1 to 2 lb. per square are required. Special
ties or clamps are used for fastening this material to steel shapes
(purlins, beams, etc.).
Crimped sheets usually have two or more crimps running
lengthwise of the sheets. One of the edge crimps should be of a
type to reduce possible leakage. Side laps may be 2 to 3.5 in.
End laps are usually 6 or 8 in. for roofs and 4 or 6 in. for siding.
Extra material for laps will be about 15 per cent with 2-in. side
laps and about 22 per cent with 3.5-in. side laps. About 5 per
cent should be allowed for cutting and fitting waste in addition
to the allowance for laps. Crimped sheets weigh about the.
same per square as corrugated sheets of the same gage. See
Table 10-4 for square feet of corrugated steel required per square
of roof surface, see Table 10-5 for weights per square foot, and
Table 10-6 for approximate weights of materials required per
Corrugated sheets with 1.25- and 2.50- (actually 2.67-) in.
corrugations are commonly used for siding and roofing. The
26-in. width usually has both edges turned the same way, and
the side lap is about 2.00 in. (about one 2.50-in. corrugation).
The 27.5-in. width usually has one edge turned up and the other
down, and the side lap is 3.50 in. (about 1.50 times the 2.50-in.
corrugations). End lap is about 4 to 6 in. for siding and 6 to
8 in. for roofing. Corrugated roofing should not be used when
the pitch is less than 3 in 12. Steel flashing is required on ridges,
valleys, eaves, windows, etc., whenever necessary to ensure
Approximate gross areas of corrugated sheets required are:
27.5-in. width '= net area + end laps + 15 per cent for side
laps of 1.5 corrugations.
26-in. width = net area + end laps + 10 per cent for side
laps of 1 corrugation.
In general, about 15 per cent is sufficient for end and side laps
for the 26-in. width and 22 per cent for the 27.5-in. width. From
5 to 10 per cent in addition may be allowed for waste caused by
cutting and fitting.
Table 10-4 gives the square feet of corrugated steel required
per square of roof surface.
TABLE 10-4.-APPROXIMATE SQUARE FEET OF CORRUGATED STEEL REQUIRED
End lap, in.
Gross Net Side
width, width, lap, 4 5 6 7 8
in. in. in.
Square feet for one square
26 24 2.0 113 114 115 116 117
27.5 24 3.5 120 121 122 123 124
Table 10-5 gives the weights per square foot of flat aid corru-
gated sheets in black (unpainted), painted, and galvanized
TABLE 10-5.--WEIGHTS OF FLAT AND CORRUGATED STEEL PER SQUARE FOOT
Flat sheets Corrugated sheets
U. S. Thick-
gage ness, in. Galva- Galva-
IBlack Painted i Black Painted Ganiz
22 0.030 1.25 1.26 1.41 1.35 1.36 1.51
24 0.024 1.00 1.01 1.16 1.08 1.09 1.25
26 0.018 0.75 0.76 0.91 0.81 0.82 0.98
27 0.0165 0.69 0.70 0.84 0.74 0.75 0.91
28 0.015 0.63 0.64 '0.78 0.67 0.68 0.84
29 0.0135 .. . . 0.72 .... I ... 0.77
To obtain weights per square, multiply the proper tabular value
by the number of square feet of steel required per square..
ROOFING AND FLASHING 297
298 CONSTRUCTION ESTIMATES AND COSTS
STable 10-6 gives approximate weights per square for 26- and
27..5-in. widths, based on 15 per cent for. laps and 5 per cent cutting
waste for the 26-in. width and 22 per cent for laps and 5 per cent
for cutting waste for the 27.5-in. width.
TABLE 10-6.-APPROXIMATE WEIGHTS OF CORRUGATED STEEL REQUIRED
26-in. Width 27.5-in. Width
U. S. Gage
Black -Galvanized Black Galvanized
22 162 181 172 192
24 130 150 137 159
26 97 118 104 125
27 89 109 94 116
28 80 101 85 107
29 ... 92 ... 98
Weights of painted steel will average 1 to 1.5 Ib. per square
more than those of the corresponding gage of black-finish steel.
Diagram 10-4 (page 615) may be used for estimating the cost
per square of metal roofing.
14. Flashing.-Materials used for flashing may be tinned,
painted, or galvanized steel; copper; or asphalt. Metal sheets
or shi, gles about 5 by 7 in. in size are usually used around
chimneys and small openings. For valleys (and sometimes for
ridges), rolls of metal or asphalt roofing may be used. The cost
of metal flashing will depend upon the material, gage, width,
and length. Valley strips are usually 12 to 18 in. wide. Ridge
strips may be 9 or 12 in. wide. Cost of tinned-steel flashing
shingles 7 by 9 in. may vary from about $1 to $1.50 per 100.
Cost. of copper flashing shingles or strips may vary from $0.25
to $0.50 per lb. Steel valley, 14 to 18 in. wide, 28 gage gal-
vanized, comes in rolls about 25 or 50 ft. long. The 25-ft. rolls
may cost $1 to $2 per roll, depending on width and gage. Asphalt
valley strips come in rolls about 18 in. wide and 36 ft. long, and
cost about $1 per roll. Asphalt ridge strips come in rolls about
9 in. wide and 30 ft. long and cost about 80.50 per roll.
15. Roofing Trim.-Roofing trim such as ridge strips, gutters,
and downspouts are usually estimated per lineal foot. Ridge
ends (finials), end caps, eaves trough corners, elbows, shoes,
ROOFING AND FLASHING 299
drop outlets, cutoffs, etc., are usually estimated by the piece,
other details being given. Hooks, hangers, etc., are listed by
the dozen. Approximate prices (1939) are as follows:
Ridge strips, 28-gage galvanized steel........ $0.40-$0.70 per 10 lin. feet
Finials. ................................... 0.15-0.40 each
Gutters, 26- to 28-gage, galvanized steel, 3.5-
6 in. ................................... $0.40-$1.00 per 10 lin. feet
Rain pipe, 26- to 28-gage, galvanized steel, 3-
4 in.................................... 80.50-S1.00 per 10 lin. feet
Drop outlets, elbows, shoes, corners, etc...... $0.15-80.50 each
Rain-pipe cutoffs .......................... 0.75-81.25 each
These prices are approximate; hence, dealers' price lists should
be consulted when preparing estimates. Special work should be
estimated separately by a competent tinsmith.
16. Sheet-metal Work.-Frequently most of the items listed
under roofing trim are classed as sheet-metal work. These items
are purchased ready made from the dealers, and the contractor
erects them. On some jobs, the sheet-metal work (providing
of the materials and their installation) is let as a subcontract.
For estimates on special work such as cornices, skylights, ven-
tilators, and windows, the estimator should consult the manu-
facturer or dealer and secure his prices.
17. Labor.-The cost of labor for roofing and flashing will
depend upon kind of labor (roofers, carpenters, tinsmiths,
painters, handy men, helpers, etc.) used, their hourly output,
and hourly wages. The hourly output will depend on the
particular job (cutting and fitting required, materials to be used,
etc.) and upon the skill and inclination of the workers. Labor
wages may vary from $0.25 to $0.75 per hour for unskilled labor
and from $0.50 to $2 per hour for skilled labor.
For roofing work, the men should be organized in gangs con-
sisting of both skilled laborers and helpers (if local rules permit
the use of helpers). If a gang consists of three or more men,
one should be the straw boss, or foreman. The number of men
in the gang will vary with the amount of roofing and kind of
material. For ordinary shingling or the laying of asphalt roofing,
a gang may consist of two to five men. For built-up or com-
position roofing, one or two men may be needed on the ground
for about every two men on the roof. Enough helpers should be
available to do the work on the ground and to keep the roof men
CONSTRUCTION ESTIMATES AND COSTS
supplied with materials. The proportion may vary from about
ont helper for four roofers to one helper for one roofer. If the
gang is large (say five or more men) or if two or more gangs are
used on the job, a foreman should be provided to supervise the
work and keep the men busy.
TABLE 10-7.--APPROXTMATE LABOR-HOURS REQUIRED PER SQUARE FOR
APPLYING ROOFING MATERIALS
Hours per square
Roofing materials Simple Complex
Shingles, wood, single.............................. 2- 6 5-10
Asphalt, single ................................ 2- 6 5-10
Asphalt, 3 and 4 strip.......................... 1- 4 3- 6
Asbestos, single ................... ............ 3- 8 5-12
Slate, single.................................... 3- 8 5-12
Metal, single .................................. 3- 6 5-10
Tile, clay.................................. ..... 4-10 6-16
Metal........................................ 3- 9 6-15
Asphalt roll roofing................ .... ............ 0.5- 2 1- 3
Canvas, laying canvas................. ........... 1.5- 2.5
Painting, per coat ............... ............. 0.5- 1.5
Composition felt and tar or asphalt:
2-ply and 2-coat................................ 2 4
2-ply and 3-coat................................. 2.5- 5
3-ply and 3-coat................................ 3 6
3-ply and 4-coat................................ 3.5-- 7
4-ply and 4-coat................................ 4 8
4-ply and 5-coat................................ 4.5- 9
5-ply and 5-coat................................ 5 -10
1 coat gravel or slag............................ 0.5- 1.5'
1 coat tar or asphalt............................. 0.5- 1.5
Metal, tinned, soldered, -14 X 20 .................... 6 9 8-14
20 X 28.................... 4 7 6-10
Tinned, seamed, 14 X 20........................ 5 7 6-12
20 X 28 ....................... 3 6 9 5- 9
Crimped and corrugated on wood sheathing ........ 0.5- 1.5 1- 3
On metal frame .............................. 1.0- 2.5 2- 5
Roofing paper and felt............................ 0.5- 1.5 1- 2.5
Tables 10-7 and 10-8 give approximate labor required for
different kinds of roofing and flashing work. The labor-hours
given refer to work on buildings of about two or three stories or
less in height. For multistoried buildings, additional labor time
ROOFING AND FLASHING 301
must be allowed for hoisting materials to the roof. From 0.2 to
0.5 additional labor-hours per square per story may be required,
depending on the materials used and hoisting equipment avail-
able. If materials have to be carried by the men, 0.4 to 1.0
additional labor-hours per square per story may be needed.
TABLE 10-8.-APPROXIMATE LABOR-HOURS REQUIRED FOR ROOF FLASHING
Kind of work Unit of Labor-
Ridges.................. 100 lin. ft. 1 3
Valleys................. 100 lin. ft. 1 3
Flashing................ 100 lin. ft. 3 -10
Flashing................ 100 shingles or pieces 3 8
Gutters................. 100 lin. ft. 2 5
Downspouts............. 100 lin. ft. 2 5
Miscellaneous items...... Each 0.1- 1.0
When the sheet-metal work is let as a subcontract, the esti-
mator may use the subcontractor's figures and will not need to
make his own estimate of materials and labor for this work.
Diagram 10-6 (page 617) may be used for estimating labor costs
of roofing per square or per 100 lin. ft.
18. Equipment.-The equipment required will vary with the
kind of roofing and the conditions on the particular job.
Shingling. Hand tools, strips for footholds, ladders, and
sometimes hoists and scaffolds.
Tile. About the same as for shingling job.
Asphalt roll. Hand tools, including brushes, ladders, some-
times special shoes with rubber or nonskid soles, and sometimes
hoists and scaffolds.
Canvas. Hand tools, ladders, painting tools.
Composition. Hand tools, brushes, heaters, pails, ladders,
and sometimes hoists.
Metal. Hand tools including metal shears, special tools for
bending seams, soldering outfits, ladders, and sometimes scaffolds
and hoists. Corrugated and crimped roofing will not require
seaming or soldering tools.
Roofing paper and felt. Hand tools, ladders, and sometimes
scaffolds and hoists.
Failing tiling: here the fault seems to lie in inferior modern
tiles and not in the fixings
These attractive clay pantiles are now rarely made, but they
may be permeable by driven snow
The most careful thought is needed when the old covering
is so unsound as to be unusable. It may then be necessary
to consider substituting a new, cheaper material for the
old; and here the change in the appearance of the building,
as well as the introduction of a material of perhaps lower
standard, are matters not to be undertaken lightly. The
extreme example of this type of substitution may be seen
in almost' all country districts, in the rusting corrugated
iron which now covers so many a once-attractive thatched
cottage. Another problem is the possibility of substituting
copper for lead, for reasons of cost. On concealed roofs,
this may not be a matter of architectural moment; but on
roofs exposed to view, the changed appearance is a public
concern; and it is thus vital to be conscious of one's res-
ponsibility to the building, and certain of the result. This
part from practical questions of durability, which must
also be weighed in the balance, and of cost, which can best
be investigated by obtaining actual alternative estimates.
Generally speaking, the use of substitute materials should
only be resorted to when economic factors make the change
inevitable, or when the original material has shown itself
Cast sheet lead: best of all roof finishes, but less suited to
steep pitches like this at Ely Cathedral
Roof lead-work being renewed with standing welts
to be in some way seriously unsuitable for the building
which it covered. In many old buildings, the roof contri-.
Sbutes so much to the interest and attraction of the whole
that the use of incongruous materials can mean utter
5.2 Sheet roof coverings
The durability of all metal coverings is dependent upon:
(a) their degree of exposure, particularly to acid-charged
droppings and to sunlight, and (b) their means of support
and fixing, with special regard to provision for thermal
and structural movements. The most frequently used
metals are lead and copper.
Lead The great virtue of lead as a roof covering is its ease
of dressing and adaptation to irregularities of shape, and
its very great durability when properly supported and
fixed. Its one disadvantage is a liability to 'creep' when
improperly used, so that if the material is denied its natural
Molten lead runs from the heat-pan in a silver stream on
to the casting table
freedom, thermal movements may .accumulate without
returning to their original position.
Recasting sheet lead In historical times, cast sheet lead
was widely used; and this is still the longest-lived roofing
material. Old leadwork, whether cast or milled, may be
melted down and recast, either on a casting-table erected
at the site, or at the centralised workshops of one of the
several firms specialising in this type of work.
Milled lead is a perfectly good material, easier to dress than
the cast sheet, but slightly less stiff. It is, therefore, at a
disadvantage in exposed positions such as cornices and
places where rigidity is sought. A debatable point is
whether milling actually reduces the life of lead by re-
arranging its crystalline structure; this is often claimed,
but scientific proof has never been given. Since in recasting
lead, the old material is all re-used without complexities of
salvage and financial credits, cast lead is, however, in fact
no more expensive in renewing old work, especially in
relation to its undoubtedly longer life. The old lead re-
moved from the building should first have all soldered
patches cut out-other impurities can then be skimmed
from the surface of the molten metal in the 'pot'. Stories
that old leadwork contains any really significant amount of
valuable silver are mostly apocryphal, and there does not
seem to be any special reason for setting aside old lead for
return to its own particular building. If interesting old
inscriptions are found, these may be cut out and saved for
display. Otherwise the old material is all melted down, and
a proportion of new pig lead added as may be needed. The
finished lead can be varied from 6 Ibs to 9 Ibs in weight,
and cast lettering and ornamental devices can readily be
formed by pressing patterns into the sand.
Re-laying roof leadwork Sheet lead must always be firmly
and continuously supported, and the boarding carefully
overhauled and prepared. An underlay of building paper
facilitates natural thermal movements, and may help to
even out minor irregularities of the boarding. Lead should
always be protected in this way from contact with oak, so
as to prevent attack by tannic acid.
Whatever the original arrangement of the roof, the new
sheet sizes and' lengths must be carefully restricted, to
localise movements and provide plentiful expansion joints.
A maximum area of 220m2 'must normally be strictly
Leadwork, inadequately fixed, has sagged into the eaves
gutters and probably exposes gaps under the slating
insisted upon, with individual sheets not more than 3m
in length. Under proper supervision and in very sheltered
situations, particularly for internal leadwork 'protected
from sunshine, these sizes may be slightly exceeded. But
no single cause has so much reduced the life of ancient
leadwork as its layout in sheets of excessive size. If through
this fault in the past, old lead has suffered premature
decay, it is essential to remedy the design and to limit the
sheets to a proper size. This is not always easily done,
since the sheet sizes govern the position of 'drips', whose
number may in turn be limited by the available fall, for
instance behind a parapet. In tapered gutters, too, an
increased number of drips, the depth of each of which has
also sometimes to be increased for safety, can result in
embarrassingly wide gutters climbing far up the roof
slopes. But much can be done by re-planning the layout of
drips and rolls to new falls, designed upwards from the
outfall, and by introducing additional upper drips as
economically as possible. Sometimes, excessively large
sheets adjoin unnecessarily small ones, when their sizes
may be averaged out; or a very large slope can be re-laid
to cross falls in the shorter direction, with rolls laid
diagonally or crosswise. If a slope falls in more than one
Flat roof redesigned to allow proper sheet sizes. Top,
diagram showing the original layout of the leadwork. Note
size of sheets and absence of drips in internal gutter, making
no allowance for expansion. Below, diagram showing the
layout as redesigned.
direction, the roll should be formed with its open side on
the more sheltered face; and if a roll cuts diagonally across
a vertical drip, it must always be set with the open side
In relatively flat surfaces such as gutters, trouble from
inadequate drips is common; these should indeed prefer-
ably be no less than 65mm deep. If, however, as frequently
occurs in old buildings, this depth is unobtainable, the
drip may be reduced to 40mm, if some means of capillary
check is provided in the vertical face. One way of doing
this is to chamfer off the lower edge of the boarding before
Acid rivulets from tiling, especially where ljcken is present,
can cut deep runnels into leadwork
it is fixed, forming a groove into which the head of the
lower sheet can be dressed; the foot of the cover sheet is
afterwards dressed vertically past and down on to the flat.
In specifying joints between the sheets of re-laid lead, a
choice must be made between lapped junctions over a
wooden roll, and tightly-dressed open rolls or standing
welts. Where heavy traffic is anticipated, or when future
replacement of individual sheets may be required, the
wooden roll has the advantage. In this case, intersections
and the ends of rolls are 'bossed'. Generally otherwise the
open roll is best, and on any degree of slope, its tight and
continuous grip is a great help in restraining any possible
slipping of sheets. This method of fixing was general until
the 19th century; and thanks to the firm grip of the curved,
open rolls, leadwork of the upper part of Robert Adam's
dome at Kedleston Hall was found to be almost free from
movement after 200 years.
The head of each sheet on sloping surfaces is usually fixed
by two staggered rows of copper nails; but on steep slopes,
additional support can sometimes be obtained by turning
the top of each sheet over the boarding, and securing it by
nailing to the back. Whatever was there before, proper
soakers and cover flashings are the only satisfactory way of
protecting the junctions between roofs and walls or
chimneys, where any kind of fillet is bound to crack away.
It is useful to remember that sheet lead dressed into a
hollow box such as a sump is strengthened by dressing,
and that it is weakened by working when beaten over a
projecting arris. Proper fixing clips, lead 'dots' and cover
flashings must never be skimped, and a typical specifica-
tion for the renewal of roof leadwork is given below.
A difficult problem, for which no really satisfactory
remedy has yet been produced, is to prevent damage to
lead-work by the acid-charged washings from lichen grow-
ing on slates. A lead gutter immediately under stone slates
is often found to be deeply scored by this acid, in narrow
'rivulets', entirely distinct from the shallow depressions
left by mechanical wear or constant dripping water. The
damage is believed to be caused not so much by heavy rain
as by the more heavily charged dewdrops, whose action is
not diluted by washing. Since stone roofs under copper
telephone wires may often be observed to be lichen-free,
it has been suggested that one expedient may be to set a
copper strip at the ridge, or in the slope itself. Evidence of
the practical effectiveness of this method would be most
valuable. The only alternative seems to be either to set an
extra renewable overcloak at the point of maximum wear,
in which case provision must be made to resist capillary
attraction, or to reduce the width of outer lead sheets
against the foot of roof slopes, regarding them as expend-
able. In this case, the use of wooden rolls will enable indi-
vidual sheets to be renewed without damage. It is a pity
that no more satisfactory solution has yet been found.
Small dew-gutters have been rejected as being awkward
and unsatisfactory, and perhaps the only remedy may be
the introduction of an eaves course of some kind of
absorbent tiles. Other ideas would be welcomed.
The high salvage value of lead makes it a temptation to
theft, especially in isolated and unprotected positions. One
of the best and most economical precautions is by regular
floodlighting during hours of darkness, at any time
buildings are particularly at risk.
Repairs to old leadwork should always be made by lead
burning and never with solder, which has a different
coefficient of expansion and will break away. Temporary
stopping of lead cracks with the various mastics and
bituminous compounds is all a very doubtful business,
and really cannot be relied upon. In practice it usually only
conceals the trouble, while inviting further damage as soon
as the lead starts again.
Outline specification for re-covering roof in recast lead in accordance with architect's detailed site direction
1. STRIPPING AND RE-CASTINO: Carefully strip old
defective lead from roofs where directed, load and
transport from site and credit certified weights at
rates to be agreed.
Cut out and remove all solder and impurities. Care-
fully cut out any inscriptions, records of previous
re-castings, etc., and set aside for re-use as directed.
Re-cast all remaining to the following weights,
making up as necessary with virgin English lead:
Cornice 8 lb. (as 8)
Roofing generally 7 lb. (BS 7)
Dressings to wooden sills 6 lb. (as 6)
Cast new inscription and date into one sheet, as
directed by the architect.
New milled lead to be used for soakers, is to be best
English milled, of 4 lb. (as 4) weight, uniform In
thickness and texture, and free from defects.
Transport new sheet lead to site, unload and store as
directed by the general contractor.
2. RE-LAYING LEADWORK: Except where otherwise
agreed by the architect, the work throughout is to be
carried out only by registered plumbers. All new lead
to be well and neatly dressed without injury, in
sheets of specified sizes, securely fixed with copper
nails and lead or copper tacks, joints where necessary
being welted or 'burned' and not soldered, and
proper provision being made for expansion and con-
traction. Detailed site instruction on the work will
throughout be given by the architect.
3. SPECIAL PRECAUTIONS: Where excessive hammering,
etc., is liable to cause damage to internal plasterwork
or finishes, special precautions are to be taken to
avoid vibration, including the use of screws instead
of nails wherever directed.
4. SHEET SIZEs: The previous excessive sheet sizes are
not to be reproduced. New sheet sizes are not to
exceed 24 sq ft (2-20mm) in area, nor 10 ft (3m) in
length, except where specially directed by the
5. BOARDING: Boarding of all flats, gutters, etc., is to
be carefully adapted by the general contractor, with
revised and additional drips in positions to be directed
by the architect. All projecting nails to be driven well
home and edges and irregularities planed off to provide
a continuous, smooth supporting surface. After the
architect has approved the repaired substructure, an
underlay of stout waterproof building paper, with
oth surface on both sides, shall then be laid over
e whole substructure before the lead is laid.
FIxiNG: New sheets are to be fixed at the head with
o staggered rows of copper nails with 10mm flat
ads at 75mm centres and 75mm apart. Drips at the
nt between the top of each sheet and the foot of
c next are to be provided, each of depth at least
mm whenever the old boarding layout allows.
here existing boarding does not permit drops of this
epth and cannot be'Wadited to provide it without
rising gutter heads to an impracticable extent, or
creasing gutters to an uneconomic width, drips may
retained where directed at a minimum of 38mm
eep. The top of the lower sheet must, however, in this
ase be dressed into an anti-capillary groove half-way
Sthe vertical face of the drip, the foot of the upper
eet being dressed past and down on to the fiat.
inclined roofs exceeding 15 deg. in pitch, drips
ay be replaced by overlaps, to be at least 150mm
ep, measured vertically.
he sides of all sheets are to be fixed with lead or
upper tingles 65mm wide, securely nailed down and
med into hollow rolls. Alternatively, where directed,
xings may be made by dressing around wooden
Is, with bossed ends and intersections. The foot of
ach sheet more than 750mm wide is to be similarly
supported by lead or copper clips.
Lead 'dots' are to be formed to support all vertical
faces as directed, and whether or not these were
originally so provided, and wiped over countersunk
brass screws and washers at centres not exceeding
750mm in any direction.
7. VERTICAL ABUTMENTS: Against all vertical abut-
ments, form 150mm upstands and protect with cover-
lashing inserted 25mm into walling, new grooves
being cut for the purpose where necessary. Cover-
flashings are to be secured with lead wedges at 450mm
to 600mm centres, pointed in with cement mortar,
and dressed down at least 100mm over upstands.
Sheets are not to exceed 2-4m length, to be lapped at
least 100mm, and supported at intervals of not more
than 750mm by means of 65mm lead or copper clips
securely fixed to walling and turned down behind
flashings, then dressed back 25mm over outer face.
Secret gutters against abutments are in future to be
avoided. Where specially permitted, they are to be
formed of 6-lb (as 6) lead, copper-nailed to roof
'boarding under the last slate, dressed over a tilting
fillet and across the gutter, then turned up and
protected as described above.
8. VALLEYS: Valley boarding, adapted and repaired as
directed, is to be recovered with 7-lb (as 7) lead,
dressed to slope of boarding, turned over tilting
fillets at each side, and carried up under re-fixed
slates to a distance of at least 75mm measured vert-_
ically. Upper end of each sheet to be close copper-
nailed and lower end lapped at least 150mm, measured
9. RIDGES AND HIPS: To be covered with 7 lb (as 7)
lead in sheets not exceeding 2-4m in length, with
150mm lap at joints, dressed over rolls and 150mm to
165mm down slates on each side. All dressings to be
firmly held at 750mm intervals by double lead clips
65mm wide, fixed under rolls and carried down
under wings, then dressed back 25mm along upper
10. GUTTERS: Tapered gutters are to be reformed by
the general contractor in accordance with the archi-
tect's detailed site instructions, with drips at intervals
as specified above, and from width at least 230mm at
lowest point. Before refixing of slating, re-dress
gutters with 7 Ib (Bs 7) lead carried 150mm up slope
and over continuous tilting-fillet. Form upstands and
cover-flashings at abutments as specified above.
Downpipe boxes to be re-formed where directed, and
of dimensions at least 230 x 230mm x 100mm deep.
Cut away masonry of parapets and provide 7 lb (as 7)
lead overflow spouts to each box as directed, dis-
charging through parapet and clear of wall externally.
Back-gutters behind chimneys to be re-dressed with
7 lb (as 7) lead dressed-at least 100mm around each
angle of chimney.
11. DORMERs: Boarding to be made good by general
contractor all as directed, and any particularly uneven
old boards faced with approved outdoor quality hard-
board, securely nailed down.
Cheeks to be recovered 'with 6 lb (BS 6) lead dressed
over top board and nailed thereto on reverse and also
supported by wiped lead 'dots' as specified above,
The front edge to be dressed around the corner post,
securely copper-nailed and welted back over nail
heads. Tops of dormers to be re-covered with 6 lb
(as 6) lead as for flats, with lead or copper fixing tabs
at all exposed edges.
Dormer and chimney aprons to be dressed at least
100mm around angles, and to have 230mm inclined
apron supported by lead clips at not more than
750mm intervals. Soakers against dormers and
chimneys to be 25mm longer than slates and turned
up under cover flashings and dormer cheek leadwork.
12. DRESSINGS TO CORNICES AND LEDGES: Whether or
not these were originally so provided, all cornices and
water-holding or permeable ledges of stonework are
to be carefully dressed with 8 Ib (Bs 8) lead with
welted expansion-joints at 2m to 2-5m intervals and
dressed at least 20mm into joints of walling. All ledge
and cornice dressings are to be fixed by lead dots at
distances not exceeding 750mm, utilising original
mortices where possible. Where possible damage to
stonework would be avoided thereby, old 'dots' may
with the permission of the architect be cut off flush,
and fixings obtained by large-headed, coarse-threaded
brass screws and washers driven into the retained
lead plug, the upper part of the new 'dots' being wiped
13. REPAIRS: Thoroughly inspect and check over all
remaining existing beadwork to roofs throughout and
repair as directed in detail by the architect.
Cut out all soldered or inadequate patchings, iron
nails and other temporary fixings; and repair by
burning-in new pieces all of weight to match existing.
Re-dress and re-fix all loose and displaced leadwork
as directed, making up with new lead or copper clips,
and copper fixing nails where these are deficient or
inadequate. Where severe acid cutting is apparent on
sloping faces (e.g., under drips from slating at heads
of dormers) these are to be reinforced where specially
directed by temporary 4 lb (as 4) milled lead. over-
14. DUCKBOARDS: Overhaul dnd renew all duckboards
as directed in creosoted deal, so as to permit free flow
of water from melting snow. Repair and replace all
defective and deficient guards to downpipas afid other
constricted points as directed where blockages could
otherwise be caused by leaves and rubbish.
15. COMPLETION: All roof plumbing works are to be
approved in detail by the architect before the oper-
atives leave the site. Leave all leadwork in a sound
and weather-tight condition and remove all tools,
plant and equipment and unused materials. Carefully
clean out all gutters with wooden shovels; wash
down and leave all tidy on completion.
Copper Copper has been used for roofing buildings for
many hundreds of years. The green 'patina' which the
material develops is itself an attractive and important
feature of many architectural exteriors; and copper is
much lighter than lead. It is also cheaper, although enjoy-
ing a slightly less venerable old age than its sister metal.
The greatest danger to copper on a roof is from excess
working, either when it was originally dressed, or through
'drumming' due to inadequate support. This causes fatigue
and eventually cracking, and the Copper Development
Association recommend that sheets should not be repaired
with soldered patches.
_. -. .. e
Wotton House, Buckinghamshire: Soane's copper roofing
in sheets of excessive size, has now buckled by thermal
Where a copper roof has failed in any degree, therefore, it
is usually more economic to strip and re-lay it throughout.
The boarding can also then be overhauled and repaired,
with particular regard for the smooth and continuous
support which the metal requires. The substructure should
be closely examined by the architect before the new
covering is laid. Felting is desirable to prevent chafing, but
should be non-bituminous: it is laid with butt joints and
fixed by copper nails.
Copper for re-roofing should be thoroughly annealed and
of 22 or 23 gauge. Samples may be tested by weighing and
by a 'double-bend' test described in BS 1569. Although old
copper can in fact be re-annealed, this is seldom worth
while. The new metal is fixed in sheets not more than 1-8m
to 2-4m long, jointed head-to-foot by double welted
seams. The area of sheets should not exceed 1-30m2; if
sheets of greater size are used, there is a risk not only of
drumming and fatigue, but of thermal movements lifting
whole sheets of copper from the roof.
For the side joints between sheets, there is again the choice
between standing seams and welting over wooden rolls.
Flat-topped rolls are better than the pointed type, in
forming which the sheets may accidentally be dressed up
and away from the substructure.
A system of 'economy' copper roofing was at one time
developed, in which sheets of extra size were held in place
by sliding clips, permitting ready expansion and contrac-
tion. Where for any reason the traditional layout is im-
possible, the method may enable a defective copper roof
with excessive sheet sizes to be relaid, without entailing
extensive carpentry alterations to the boarding system or
Copper must not be jointed or patched with solder, which
has a different expansion rate and will come away. On the
flat, a fall of at least 1 in 6 is recommended, with drips
at least 50mm deep at every 3m: the rolls are usually
staggered at the drips to facilitate working. A Scandinavian
practice is to paint the joints with raw linseed oil before
welting.The re-laid copper roof should be very closely
examined on completion, with special regard to the absence
of working cracks, and to firmness and continuity of sup-
port. Lastly, as with any metal roofing, it is particularly
important to prevent damage during adjoining works, as
can so easily happen from a dropped chisel or an in-trodden
nail: really adequate protection of the finished job is quite
A typical specification for re-covering roofs in copper is
given on page 103.
Other substitute materials Aluminium is a young material,
and has not yet had the opportunity to show its paces for
such long periods as copper and lead. It dresses well and
when proved by time, may well earn a place alongside the
other metals suitable for re-roofing old buildings. The chief
drawback at present is the practical difficulty of any simple
kind of jobbing repair except the replacement of complete
Other useful materials where only a limited life of a
generation or so is called for include the various rubberised
and reinforced bituminous felts. The latter can be readily
dressed when heated, and hold their shape well once set in
position. But in the repair of old buildings whose life is
commonly measured in centuries, such materials cannot,
of course, hold comparison with metals such as lead and
The various types of asphalt are nowadays used on old as
Outline specification for re-covering roof in sheet copper in accordance with architect's detailed site direction
1. sTRIPPING o0. COPPER: Carefully strip old defective
copper from roofs, etc., as directed, load and transport
from site, and credit certified weights at rates to be
2. NEW MATERIALS: All hew copper used shall conform
to the requirements of as 1569 .1965, and shall be of
24, 23 or 22 standard wire gauge, except as otherwise
directed, and of deaCa4 ft temper.
Throughout the entire new copper roofing works, no
iron nails shall be used in contact with the copper as
before. All copper shall be fixed with copper nails or
3. RE-LAYING COPPERWORK: The work throughout is to
be carried out by experienced plumbers or recognized
copper-roofing specialists. The whole of the work in
connection with the new copper roofing is generally to
be carried out on the site, and in accordance with
detailed instructions to be given by the architect.
All new copper sheet is to be laid truly flat, flattening
being carried out on the bench. Before laying, the
material is to be prepared by cutting, bending and
seaming to fit accurately into the bay of the roof for
which it is intended: thus avoiding unnecessary
forming, dressing and cold working. Due allowance is
to be made in all dimensions for expansion and
4. SPECIAL PRECAUTIONS: Where excessive hammering,
etc., is liable to cause damage to internal plasterwork
or finishes, special precautions are to be taken to
avoid vibration, Including the use of screws Instead of
nails wherever directed.
5. SHEETr SIES: The previous excessive sheet sizes are
not to be reproduced.
Except where specifically directed otherwise, new
copper sheets are not to exceed 600mm in width.
Areas of individual sheets in 22, 23 and 24 s.w.g.
copper are not to exceed l'30ms and in 26 s.w.g.
sheet where used, 1.1lm2 each.
6. BOARDING: The boarding of all flats, gutters, etc.,
is to be carefully adapted accordingly by the general
contractor 'with new drips wherever necessary, in
positions to be directed by the architect. All projecting
nails are to be driven well home, and edges and
irregularities planed off to provide a continuous,
smooth supporting surface.
7, FELT: After detailed approval of the repaired sub-
structure an underlay of felt is to be laid over the
whole of the boarding to receive the new copper. The
felt is to be type 4A (ii) brown impregnated flax,
known as inodorous felt No. 1, 23kg per roll, con-
forming to as 747: 1968/70. Alternatively, Fibirine
Felt may be used.
The felt is to be laid butt jointed, and secured with
8. SEQUENCE OF OPERATIONS: After the roof surface has
been prepared, it is to be brushed clean and laid with
sufficient felt for a day's work. The prepared new
copper is then to be laid in the following sequence:
(c) drop aprons;
(d) main roof sheeting;
(e) cover flashings.
9. FIXING: All free edges of the new copper are to be
properly secured by means of copper cleats as directed
by the architect. These cleats are to be not less than
50mm in width, and secured to the roof boarding, or
passed through slits or joints in the roof boarding and
secured on the underside. Cleats 50mm wide are to
be fixed at 380mm centres in all joints from eaves to
ridge, at 300mm centres on verge edges, and two per
bay at drips, eaves and ridges generally. Transverse
joints are to be fixed with one 75mm wide cleat in the
centre of each double lock cross welt, and two 50mm
wide cleats in each single lock cross welt. Each cleat
is to be fixed close to its right-angled turn by a
minimum of two copper nails or brass screws; the
tail end of the cleat is then to be turned back to cover
the heads of the nails or screws so as to prevent all
abrasion of the under surfaces of the copper when
any movement takes place.
Ridge to eaves joints are to be formed with standing
seams or batten rolls as directed. Standing seams are
to be formed to a nominal height of 25mm and are to
be spaced generally at 540mm centres. Batten rolls
are to be formed to the following minimum sizes:
Height 38mm, width at base 45mm, width at top
32mm. The finish of batten rolls at the eaves may
either be splayed or vertical, as directed on site.
On roofs not exceeding 5 deg. In pitch, transverse
joints are to be formed with drips not less than 50mm
in height. On roofs between 5 deg. and 60 deg. in
pitch, double lock cross welts are to be used for
transverse joints, and are to be staggered in alternate
bays. Transverse joints to roofs exceeding 60 deg. in
pitch may be single lock welts.
10. VERTICAL ABUTMENTs: Against all vertical abut-
ments form 150mm upstands and protect with cover
flashings, joined to upstand by means of 25mm single
lock welt where practicable. Alternatively, the cover
flashings may be beaded and held to the wall by
means of a copper strap, fixed behind upstand and
turned down behind the cover flashing and welted
round its lower edge.
Secret gutters against abutments are in future to be
avoided. Where specially permitted they are to be
formed of 26 s.w.g. copper, copper-nailed to roof
boarding under the last slate, dressed over a tilting
fillet and across the gutter, then turned up and
protected as described above.
11. VALLEYS: Valley boarding is to be adapted and
repaired as directed, and suitable tilting fillets pro-
vided to enable the sheeting in the gutter to be joined
by means of a single lock welt to a continuous fixing
strip, nailed to the tilting fillet so as to allow for free
movement of the copper in the gutter.
Lengths of copper in valley gutters are to be joined by
double lock cross welts where pitch is 60 deg. or less.
For steeper pitches, single lock welts may be used.
12. RIDGES AND HIPS: -Ridges and hips to all roofs
formed with standing seam down-joints are to be
finished with standing seams welted in, or with ridge
rolls, as directed.
On roofs formed with batten roll down joints, the
ridges and hips are similarly to be finished with
batten rolls 65mm to 75mm in height and approxi-
mately 50mm wide at the base.
13. EAVES: The eaves are to be finished by means of a
separate and continuous fixing' or lining strip cut
from half-hard copper strip, secured to the fascia by
copper nails or brass screws.
A drop apron made from dead soft temper copper is
to be secured to the bottom edge of the lining plate,
and at eaves level is to be turned outwards at 90 deg.
to the fascia. Cleats 50mm wide, two per bay, having
previously been fixed to the roo decking, are to be
folded over this 90 deg. flange. The roofing sheets are
then to be turned over and under this projection, and
finally dressed down to form a single lock welt on the
14. GUrraRs: Tapered gutters are to be reformed as
necessary by the general contractor with drips at
intervals of from 2m to 3m and from a width of at
least 230mm at the lowest point. Detailed site Instruc-
tion on the whole of this work will be given by the
In long gutters from 6m to 15m 'where excessive
expansion takes place, special expansion joints are to
be formed in the new copper to accommodate such
movement, as shown in the graph in CDA publication
No. 42, Copper Weatherings and Flashings.
Re-line gutters with new copper sheet, with upstands
and flashings as described above.
Reform downpipe boxes where necessary, of dimen-
sions at least 230mm x 230mm x 100mm deep. Cut
away masonry of parapets as directed and construct
overflow spout to each box, of 26 s.w.g. copper, to
discharge through parapet and clear of wall externally.
Back-gutters behind chimneys are to be dressed at
least 100mm around each angle of chimney.
15. COMPLETION: All relaid copperwork is to be
approved in detail by the architect before the roofers
leave the site, and left throughout in a sound and
weather-tight condition. Remove all tools, plant and
equipment and unused materials; carefully clean out
all gutters with wooden shovels, wash down and
leave all tidy on completion.
Longstraw thatch, shorter-lived and many times re-coated
well as on new roofs; but doubts have been raised in many
minds by the impossibility of being able to guarantee the
roof for any really adequate period, in relation to the life
of an old building. Continuous materials of this nature
must be supported absolutely firmly; and such details as
the function between a wooden roof and a vertical wall are
always danger points. Where a more permanent job is
impossible however, asphalt makes a sound job for its
own life span, and may usefully be employed to protect
an ageing roof for 20 or 30 years.
5.3 Unit coverings
Thatch Many more medieval roofs than would now
appear so were originally covered either with thatch or
oak shingles. Nowadays the use of thatch is mostly con-
fined to rural situations, owing mainly to the cost factor,
and to the risk of damage by fire. Thanks largely to the
encouragement of the Council for Small Industries in Rural
Areas, the craft is nevertheless very much alive and has
many young"apprentices. A thatched roof indeed offers
the best insulated covering available; but it must be
carefully maintained, and renewed at relatively frequent
Reed thatch with 'eyebrow' dormer and sedge ridging
intervals. The simple, unelaborate shapes of old thatched
roofs, formed of rough rafters and unwrought.spars, are a
perfectly adequate and suitable substructure; and there is
no need to regularise and sophisticate them. Overhanging
eaves and verges are generic to the material; but internal
valleys, parapet gables and back gutters are not, and
should be removed whenever possible. Eaves gutters are
best avoided altogether.
'Longstraw' thatch is the least durable of the family and
with a life of only 20 to 30 years, it also requires the
steepest pitch (about 50deg). The material is cheap, but
machine thrashing, which damages the straw, and rising
labour costs have made straw thatch an increasingly
uneconomical material. Reed thatch is, however, a horse
of a different colour: it is tightly 'sprung' into position
so as to present only the butts of the reeds at the surface,
and if re-ridged at intervals, may last easily 70 or 80 years.
Combed wheat reed is a little less durable, with a life of
35 to 60 years. There is no more depressing sight than
worn-out thatch; and periodical repair and attention are
essential. Damage by birds and vermin can be minimised
by wiring over the roof with a stout galvanised mesh.
(Early Roofing Materials cont'd)
Re: Tin, Zinc, Iron, etc., The Quebec Gazette, June 10, 1846.
"Cost of Roofing Materials as nearly as can be ascertained from
different Tradesmen-Labor, &c. included:-
Tin, pr. square of 100 superficial feet 3 2 6
Zinc do 2 12 6
Sheet Iron do, not painted 1 6 6
Do do, painted on both sides 1 10 6
Galvanised Iron, Do
Sheet Lead do
Slates and Tiles, do 1 2 6  1 5 0
Shingles-Pine or Cedar, do. unpainted 0 16 0
"TIN has been well tested; it stands the climate well, and in
favorable situations will last upwards of 50 years--but if much coal is used
in the neighbourhood of buildings roofed with it, its durability does not
extend above 20 years, it becoming partially decomposed by the action of the
sulphurous acid gas evolved during the combustion of the coal.
"ZINC has not yet been fairly tested; there is every reason to
doubt its permanent durability--being a granulated metal; its expansion and
contraction by heat and cold in a climate where the thermometer ranges from
30 degrees below to 120 above zero, added to oxidation, must affect it
materially. Complaints have been already made of holes appearing, as if
made with pins, in places where it has been much exposed to the action of
that atmosphere. It does not take paint readily, and if fastened with any
dissimilar metals, a galvanic action invariably takes place in wet weather.
"SHEET IRON is in reality the dearest, although apparently the
cheapest metallic covering, even if painted on both sides before being
placed"on the roof. Paint frequently blisters and pulls off. Moisture
causes rust speedily to destroy it, commencing at the nail holes and uneven
"SHEET LEAD is exceedingly expensive and lasts but a few years,
and if used on a flat roof, required to be protected from the influence of
the sun by boards.
"GALVANISED IRON is at present almost unknown here. A small
sample imported by Messrs. Wartele last fall, has, conjointly with zinc,
been placed where it can now be seen upon the houses of Mr. Noad and the
buildings of Lowndes and Patton in Paul Street. There is reason to expect
that this will be found to be the best and cheapest material for metallic
"This, like Zinc and Lead, is used in England for Water Tanks,
for horticultural and other purposes. Moisture, therefore, is not detri-
mental to it. The substance appears to be Iron in large sheets with an
A PT Vol. II Nos. 1-2 1970 Page 28
incorporated surface of Tin, and is not unlike Zinc in appearance.
"Metallic Roofs, though light, are little or no protection during
a conflagration of adjoining wooden houses. The intense heat evolved
during the short duration of the fire acts not unlike the flame of a blow-
pipe upon all objects adjacent and subjected to it. This causes the metals
to become red hot, which charring the wood beneath, causes it very quickly
"SLATES are at present but little appreciated in this country,
although they have stood the test of climate. The roof of the distillery
at Beauport, slated nearly 50 years since, is still in good condition..
"A gentlemen having lately had occasion to enlarge his house at
Beauport has removed a roof where the slates were all sound, (and have been
again used) although the wood underneath was partially decayed. Two houses
outside St. Lewis gate were covered in 1832 and have not since needed but
little, if any repairs. This material has also been lately extensively
used by Messrs. Munn, Lloyd, Lepper, McCallum, &c. From the necessity of
double laps, there is no fear of heat penetrating and charring the wood
"Although heavy, with a good under roofing of 1-1/2 inch.pine,
if well laid, there is no fear of damage from the accumulation of snow;
and in case of fire in the rooms below, from the weight of the roof the
slates would fall bodily into the building and not into the street.
"GLASS- Thick bottle or inferior plate glass tiles, supported
by iron rafters in the manner of hot..bed lights--now that all restrictions
upon this branch of trade are removed in England, is now being extensively
used there, for roofing purposes. This, whitewashed on each side in hot
weather, would make a semi-transparent and substantial covering for stores
and other buildings.
"SHINGLES last about 10 years, and are not only highly combustible,
but when ignited, from their lightness, are exceedingly dangerous to build-
ings at a distance. During the fire of 28th May, last year, a deal wharf,
adjoining the East India wharf, was on fire in several places from shingles
carried there by the violence of the gale then raging. Also, on the night
of the fire of 28th June, the fences of the fields of C. C. Stewart, Esq.,
on the St. Foy road, nearly 2 miles distant from the scene of conflagration,
were inflamed from the same cause." (A.J.H.R.)
Re: Shingle Roofing. quebec Gazette, March 21, 1816.
Charles Gouin of Ste. Anne de la Pfrade, Lower Canada (Quebec
Province) advertises 200,000 cedar shingles for sale. (A.J.H.R.)
Re: Shingle Roofing. Quebec Mercury, May 25, 1818.
Walter Gilly of Sillery near Quebec City advertises for sale
16,000 8-inch shingles of the best quality. (A.J.H.R.)
Re: Tin Plate and Sheet Iron Roofing. Quebec Gazette, June 20,
Advertisement by James George, merchant of Quebec, of tin plate
for covering houses, and sheet iron for chimney tops. (A.J.H.R.)
A PT Vol. II Nos. 1-2 1970 Page 29
Pennsylvania Packet, 8 May 1788, p. 3, col. 4.
"Just Arrived In the Birmingham, from Bristol, and for Sale by
JACOB BAKER In Market street, between Front and Second streets, A Quantity
of Tin Plates in Boxes, well assorted--and Shot from No: B to 6, on low terms."
Pennsylvania Packet, 13 June 1788, p. 3, col. 4.
"WILLIAM YOUNG, Bookseller and Stationer at the Corner of Chestnut
and Second streets, Philadelphia (has, inter alia)
American manufacture, equal in quality to the late.improved British
patent, sold by W. Young, lower than the imported."
Caswell, Prof. A. "On Zinc as a Covering for Buildings," letter
to Mssrs. Crocker, Brothers and Co., American Journal of Science and Arts
(Silliman's Journal), New Haven: Vol. XXXI, January 1837, p. 248 ff.
The reference to this article noted in Talbot Hamlin, Greek
Revival Architecture in America, New York; Dover, 1964, p. 358, was brought
to our attention by Lee Nelson. A copy of the magazine is available in the
geology library at Columbia University. The article is long and not worth
reprinting in extenso, but "zinc roofing was not very much used in this
country" remarked Charles E. Peterson in passim. Therefore, we thought that
it would be worthwhile to abstract the article as it might illuminate the
subject of zinc roofing and its problems imaginary or real in the early
The letter datelined Brown University is an answer to a previous
article on zinc as a roofing material published by a Dr. Gale of New York
in Mechanic's Magazine. Apparently Dr. Gale discouraged the use of zinc as
a roofing material upon several accounts, including the following:
1. "the difficulty of making the roof tight;"
2. "the deterioration of the water which falls from it;"
3. "the comparatively small resistance which it offers to the
progress of fire."
Prof. A. Caswell disposed of the first argument in a short para-
graph noting that zinc can be brittle and expand greatly when heated. He
finally pointed out that a zinc roof can be made as tight as any other and
that brittleness and expansion are not really considerations.
The second objection is discussed at length. "The consideration
is particularly important" Prof. A. Caswell remarks, for those who are in
the habit of using water for culinary and washing purposes. "It is alleged
that a poisonous suboxide of zinc is dissolved in the water, which renders
it unfit for cooking, and impairs its properties for washing." Prof. Caswell
studied the different properties of the various zinc oxides and carried on
tests. He came to the conclusion that "water suffers no deterioration what-
ever from the zinc."
A PT Vol. II Nos. 1-2 1970 Page 37
(Early Roofing Materials cont'd)
The third objection is based upon the fact that zinc melts at a
low temperature. "Zinc melts at 7000F.," Prof. Caswell points out "or a
little below red heat. Whenever, therefore, the heat from adjacent build-
ings is less than of redness, zinc would afford as complete protection as
copper or iron." He then continues "complete protection against fire is
perhaps unattainable...I am not aware that the following construction for
a roof has ever been tried. ...Let the rough boards of the roof be covered
with a thick coating of common lime mortar then lay down the ribs, if I
may so call them, for the zinc plates then cover the whole with zinc,
according to the most approved method of applying it." (Abstract by Jacques
Board roof, Hudson's Bay Company post on Mackenzie River, North West
Territories, as about 1900
photo by C. W. Mather in Alberta Provincial Archives
Vol. II Nos. 1-2 1970
(Early Roofing Materials cont'd)
Round logs from fifteen to twenty feet long, without the least dressing, are
laid horizontal, over each other, and notched at the corners....the roof is
covered with the rinds of birch or fir trees and thatched either with spruce
branches or long marine grass that is found washed up along the shores.
Poles are laid over this thatch, together with birch wythes to keep the
whole secure." (Contributed by A. J. H. Richardson)
Ed. Note: In 1960 A Guide to American Trade Catalogs from 1744
to 1900, compiled and edited by Lawrence B. Romaine, was published by R.
R. Bowker, New York. (See also the review in this issue). The book has
chapters on architectural building materials, hardware, stoves and heating
equipment, among other subjects. The following extracts cover catalogs
about roofing materials from 1850 to 1900.
1850 New York & Liege, Belguim
McCALL & STRONG. (Late Mosselman,
agent.) I11. catalog of zinc roof-
ing materials. 8vo., 40pp., wrap.
1853 New York
MOREWOOD, GEORGE B. & CO. Ill.,
desc. and priced catalog of galvan
ized tinned iron and plumbic zinc
goods. 32pp., wrap.
1854 New York
LEFFERTS, MARSHALL & BROTHER.
Patented galvanized iron for roofs
etc. Tests. 4x7, 49pp., ill.
1857 New York
VIEILLE MONTAGNE ZINC MINING CO.
Ill. and priced circular on zinc
ZINC ROOFING & ORNAMENTAL WORKS.
Ill. catalog #1.
GARRY IRON ROOFING CO. Ill. catalog
pat. iron roofing for all building.
Largest producers in the world.
16mo., 20pp., pict. wrap.
1874 New York
NEW YORK SLATE ROOFING CO. George E.
Glines patent slate roofing paint,
cement, roofs, tests. and list of
users. 8vo., 80pp., ill.
c.1875 Delpsburg & Philadelphia
EMPIRE SLATE WORKS. J.B.Kimes & Co.
4 page col. ill. folder of slate man-
tels, ice boxes, pulpits, pedestals,
roofing, flooring tiles, etc.
MINNEAPOLIS GALVANIZED IRON CORNICE
WORKS. Catalog of designs of archi-
tectural sheet metal ornaments, cor-
nices, window caps, ventilators, iron,
slate and gravel roofing. 4to., fine
Vol. II Nos. 1-2 1970 Page 50
CINCINNATI CORRUGATING CO. Ill.
catalog of superior corrugated
sheet iron, steel and zinc
roofing. 16mo., 16pp., wrap.
1884 New York
JOHNS, H. W. MFG. CO. Est. 1858.
Ill. catalog of standard asbestos
materials for roofs, walls, pipes,
etc. 12mo., 48pp., pict. wrap.
c. 1889 New York
------Ill. folder of roofing
and coverings. Pict. wrap. in
1884 Canton, 0.
SNYDER, T.C. & CO. Ill. catalog
of improved sheet iron roofings
and iron ore paints for roofs.
16mo., 16pp., pict. wrap.
LLOYD IRON ROOFING & PAINT CO.
Ill. catalog of corrugated iron and
sheet metal roofing in all its
branches. 12mo., 32pp., pict.
INDIANA PAINT & ROOFING CO.
Catalog of rubber roofing,
sheathing, paints, marbelized
mantels, etc. 8vo.,ill., pict.
-----Free booklet on rubber
roofing, slate mantels, etc.
8vo., 40pp., pict, wrap. of
SAGENDORPH IRON ROOFING,CORRUGATING
& PAINT CO. Ill. catalog of roofing
materials. 12mo., 32pp., pict.wrap.
MERCHANT & CO. Ill. catalog of
roofing plates and tin roofs.
1890 Camden, N. J.
FAY, W. H. Fay's waterproof build-
ing manila for roofing. 8vo., 32pp.,
ill. of dwellings and buildings in
many states using Fay's products.
1893 New York
NEW YORK IRON ROOFING & CORRUGATING
CO. Ill. catalog of roofing. 16mo.,
10pp., tests. from Pa., Ind., etc.
1895 St. Louis
SOUTHER, E. E..IRON CO. Ill. catalog
roofing department roofing, siding,
ceilings, etc. 7x10, 40pp., wrap.
1896 Salem, 0.
MULLINS, W. H. CO. Ill. catalog of
architectural sheet metal'work, art
metal roofing, cornices, crestings
and statuary. Plates of statuary for
Cotton States and International
Exposition, factory interiors, etc.
Tall 4to., 172pp., dec. cl.
BARRETT MFG. CO.
Wis. Catalog B -
etc. 8vo., 32pp.
Mills at Beliot,
, ill., wrap.
c.1900 Easton, Pa.
GENUINE BANGOR SLATE CO. Slate and
its uses. 2nd ed., 4to., 74pp., ill.,
ol. II Nos. 1-2 1970
and it should never be less than one-sixth. The most usual pitch for slates is when the
height is one-fourth of the span, or when the angle with the horizon is 261 degrees.
The pediments of the Greek temples make an angle of from 12 to 16 degrees with the
horizon; the latter corresponds nearly with one-seventh of the span. The pediments of
the Roman buildings vary from 23 to 24 degrees: 24 degrees is nearly two-ninths of the
span; and is the angle Palladio recommends for roofs in Italy.*
The kinds of covering used for timber roofs are copper, lead, iron, tinned iron, zinc, slates
of different kinds, tiles, shingles,t reeds, straw, and heath. Taking the angle for slates to
be 262 degrees, the following table will shew the degree of inclination that may be given for
Kind oc Inclination to thehori- Height of roof in parts Weight upon a square
Kind of covering on in degrees. of span. foot of roofing.
5 copper 1"00 lbs.
Copper or lead .................... 3 50 4 lead 700b
Slates, large. .................... 22 0 1 11'20.
( from 9"00
Ditto, ordinary................... 26 33 )frto 5'00
Stone slate .................... 29 41 4 23-80
Plain tiles........................ 29 41 4 17-80
Pan-tiles ........................ 24 0 2 6-50
Thatch-of straw, reeds, or heath ...... 45 0 straw 6-50
Force of wind does not generally exceed 40b00
OF THE FORMS OF ROOFS FOR DIFFERENT SPANS.
164.-A roof for a span of from 20 to 30 feet may have a truss of the form shewn in
Plate V. fig. 49. Within the limits above stated the purlins do not become too wide
apart, nor the points of support for the tie beam; and in the table, No. 5, at the end of the
volume, the scantlings of the timbers are given according to the length and bearing of the
different parts. The figure (49) is drawn with a parapet on one side and eaves on the
165.-For'spans exceeding 30 feet, and under 45 feet, the truss, exhibited in Plate V.
Architect. book i. chap. 29.
+ Shingles are now very little employed in this country, though they appear to have been much used formerly ;
(see Neve's Builder's Dictionary, art. Shingle; Britton's Archit. Antiq. Vol. II. p. 79) ; and are still much in use in the
West Indies and in America.
128 SHEET METAL WORKERS' MANUAL
their flat surfaces. The hand seamers are also used in
sets of two pairs. See Figure 91.
FLAT SEAM ROOFING
Figure 92 shows the method of making the flat seam
roofing joint and of fastening the tin to the roofing boards.
Note how the cleat interlocks permanently with the seam
and how the nail heads holding the cleats to the boards
Figure 94.-Common Roofing Folder.
are prevented from coming in contact with the tin itself.
The edges are shown trimmed flush, in order to demon-
strate that a flat seam tin roof is practically a one-piece
roof; that all seams are absolutely watertight.
Roofing Folders.-For flat seam roofing the tin plate
is edged with the wood roofing folder.
Figure 93 illustrates the adjustable wood roofing folder,
having an adjustable gauge for forming locks A to %
inch, and manufactured in 20 and 30-inch lengths.
Figure 94 illustrates the common roofing folder, manu-
factured in lengths of 14, 20, 28, and 30 inches, and form-
ing locks of one size only, namely, inch.
SHEET METAL WORKING TOOLS
Sheet metal is shaped principally by being bent over
anvils of peculiar forms, known as stakes. These fit into
o a a o C0 l
P oo o E
Figure 95.-Bench Plate for Holding Stakes.
holes cut in the work bench; and to save wear of the bench
and hold the stakes rigid the bench plate, Figure 95, is
A detailed description of each stake will not be given,
Figure 96-Revolving Bench Plate for Holding Stakes
as by reference to the illustrations, the uses of the tools
may in most cases be inferred.
.,i-i~iY-L-LUL. 19-- -.--._5~-LI-IL;~C~C-\Y ; Ilh:.:__i.i ---b.C _- .~---i;i~li i
--- -------r~,-r~:ars~.r~Tnm~ar~;r '
128 SHEET METAL WORKERS' MANUAL
The bench plate shown in Figure 96 will prove very
handy where only a few small stakes are used and is
made in size 83x8%3". This plate is held securely to
the bench with a clamp and handle and has a circular
swivel plate in which the stakes fit.
Figure 97 shows a stake holder and the different tools
capable of being used with it. This holder enables the
-~ ~ tO----
Figure 97.-Stake Holder with Complete Set of Stakes.
workman to use the stakes shown, in any position best
suited to the work in hand, without mutilating the bench.
One stake may be substituted for another with ease.
No. 1 is the stake holder. Nos. 2 and 9 show a "beak-
horn" stake in two pieces; No. 10 is a blowhorn stake;
No. 6 a creasing stake with horn; No. 3 a double seaming
stake; Nos. 7 and 8 a conductor stake in two pieces; No. 4
a candle-mold stake; No. 5 a needle-case stake.
Further illustrations of bench stakes are given in Fig
ures 98, 99, and 100.
SHEET METAL WORKING TOOLS
Sheet metal is scribed with the scratch awl, Figure 101,
and cut to the size of the pattern as required by means
Hand shears come in a variety of shapes. A bench
shears is shown in Figure 102.
Figure 98.-Bench Stakes.
1, Ieakhorn Stake; 2, Candle Mold Stake; 8, Blowhorn Stake; 4.
Creasing Stake; 5, Needle Case Stake; 6, Square Stake.
Hand shears, or snips, as shown in Figures 103-104, are
made with straight and curved blades.. The straight blade
shears, Figure 103, are used for general straight cutting;
the shears shown in Figure 104, known as the circular
snip, being made specially for cutting circles.
I ; ;
ti1 ..i ;
fI i *
:._~ ;r~WtiXs;;i;L-u.-.;~iZli-~UI~-~IIYZ -T
i)* -~~:VT-lr-rS~=T i(-~~Vl~il~i _--1;) n~iY~CI~Y---~-- -~ (i~VT~C;E LFC*plrl~i i-~~~--CClr~~lC-i~?;rrp~i ~ r _;
:i-i~; 11 "~'- I-lC'rn ~
i 4 $
330 SHEET METAL WORKERS' MANUAL
The Original Hand Snip.-Tapered blades for fine
work, laid steel, sharp cutting edges, sloping shoulders
to keep metal from curling, joints correctly centered to
Figure 09e-Bench Stakes (Continued).
1. Double Seaming Stake: 2, Creasing Stake, with Horn; 3, ConTpe
smith's Square Stake; 4, Hatchet Stake; 5 Bottom Stake 6, Bath
Tub Stake; 7, Bevel Edge Square Stake; 8, Round Head take.
avoid lost leverage, accurate balance and hang to prevent
tired wrists; and the bows so made as to fit the hand with-
out injury in cutting-all these are important features
SHEET METAL WORKING TOOLS
to have in mind when selecting a pair of hand snips.
The Pexto snip embodies these features. The original
Figure 100.-Bench Stakes (Continued).
1, Hollow Mandrel Stake; 2, Mandrel Stake; 3, Double Seaminl
Stake, with Four Heads, A, B, C, D; 4, Conductor Stake; 6, Tea Kettle
Stake with Four Heada.
pattern was made in 1819 and since that time this snip,
known to the sheet metal worker the country over as
Figure 101.--Scratch AwL
"P. S. & W. Co.'s 1819 Original," has made the makers
the foremost manufacturers of hand shears in the indus-
t - t -
~_-__ ;,;,,~~,~i?-ur;:-~;,v--;iti- =r---uu~~i-r;~~..Yu~Pa~;hiua~u~C~-Plua~ _
SHEET METAL WORKERS' MANUAL
Figure 105 shows a snip with the blade so shaped as to
easily cut circles, scrolls, etc., while adapted to the same
class of work as the regular snip. The jaws are beveled,
with straight cutting edges which allow the material to
Figure 102.-Bench Shear.
pass freely when cutting curves or changing the direction
of the cut.
Figure 106 shows a snip especially adapted for cornice---
and tin work. They are made to cut circles, scrolls, etc.,
Figure 103.-1819 Original Pexto Straight Snip.
very easily, but they are equally well adapted for regular
snip work. The blades are rounding and sharp pointed
and can be used for very delicate work.
Scroll and Circular Snip.-A useful combination scroll
Figure 104.-1819 Original Circular Snip.
and circular snip is shown in Figure 107. With the aid
of this snip, work can be cut on a straight line; and it will
cut circles or the radii of a circle in very much smaller
dimensions than it is possible to cut with any other snip.
SHEET METAL WORKING TOOLS
The narrow blades, having extremely sharp points, will
cut on the inside as well as on the outside of a sheet of
Figure 105.-Hercules Combination Snip.
Figure 106.-Lyon Snip.
Figure 107.-nlawk's Bil Combination Scroll and Circular Snip.
metal. The blades are hawk-billed in shape and have a
peculiar clearance bevel between the cutting edges which
SHlEET METAL WORKERS' MANUAL
SHEET METAL WORKING TOOLS 135
permits the blades easily to turn a sharp corner or work
around a small curve without buckling. The blades being
Figure 111.-Setting Hammer.
Figure 112.-Riveting Hammer.
Figure 108-Double Cutting Shears with Pipe Crimper.
1, Crimped with Attachment Fitted to Shears; 2. Old Method.
Figure 109.-Double Cutting Shears, Pocket Size.
Figure 110.-Raising nammera.
unusually narrow and ground to an extreme narrowness
at the points, they are highly valuable for cutting open-
1 2 3 4 5
Figure 113.--Chisels and Punches.
1. Wire Chisel; 2, Lantern Chisel; 3, 4, Solid Punches; 5, Prick
ings in pipe or cylinders of every description, for furnace
jackets, thimbles, tee joints, etc. They are especially
Figure 114.-Hollow Punch.
adapted for cornice-work practice in tight places, where
the regular hand snip proves cumbersome.
. . . . . .
~J2~mC~0~Il~ a II
'--- ^I ':-L--~~3~~--L~~ --'~r-r~~ _-- r- .-~-~ 1~-71E~Plll~r~-I%I;rr*~C~'Rli~I~-WP
"9~;9a~a -- aaa~la e~e~qJ~llrCllp~B*Dg~!~
SHEET METAL WORKERS' MANUAL
far as shown. The entire length of the rule is 36 inches.
The upper line is the ordinary rule, graduated by eighths
of an inch. The lower line shows at a glance the exact
circumference of any cylinder by simply ascertaining
the diameter; that is, a vessel 5 inches in diameter the
rule indicates to be 153/4 inches in circumference. The
Figure 119.-Wire Gauge, English Standard.
reverse side contains much useful information in large
plain figures regarding the sizes of sixty different articles,
such as cans, measures, pails, etc., with straight or flaring
sides, flat or pitched top, liquid and dry measure in
quarts, gallons and bushels. First is given the dimen-
sions for vessels holding 1 to 5 gallons liquid measure;
second, one-quarter to 2 bushels dry measure; third, cans
SHEET METAL WORKING TOOLS 139
with pitched tops 1 to 10 gallons; fourth, cans with flat
top 1 to 200 gallons; fifth, vessel holding 1 to 8 quarts
and 1/2 bushel to 3 bushels dry measure.
Wire Gauge.-A wire and sheet metal gauge, a neces-
sity in every shop, is shown in Figure 119. The gauge
shown is English standard and manufactured in two
sizes; namely, 0 to 36 and 6 to 36;
Figure 120.-Single Leg Extension Divider.
Dividers.-A divider, or pair of dividers, as specially
designed for the sheet metal worker, is shown in Figure
120. They are forged from a high-grade steel "scientifi-
cally tempered. One of the points is movable so that it
may be lengthened or shortened as required and will
prove a convenient scratch awl. The extension divider is
made in sizes from 6 to 10 inches inclusive.
A compass, made in sizes from 3 to 10 inches inclusive,
is shown in Figure 121. Figure 122 illustrates a combina-
tion pliers with wire cutter, made in three sizes; namely,
6, 8, and 10 inches. Figure 123 shows the tinners' flat
nose pliers, and Figure 124 a round nose pliers, made in a
1......... ......... r ^ ' i--" - -^ ^ --^ ~ - ^ ;:- -* - '7-^ ^ v ^L^.- .^ ' ^ ^ j
,,,ln.2~L~;ELC: I~ic~iSli-r~eiiY.r--L-a~fi-~X11~-~iY ~I
-I, I -
. .. V" = 210 IM- 9 5Armr
- , -:.
140 SHEET METAL WORKERS' MANUAL
variety of sizes from 4 to 8 inches inclusive. A cutting
nippers for wire cutting is shown in Figure 125.
Figure 122.-Combination Pliers with Wire Cutter.
Figure 123.-Flat Nose Pliers.
Figure 124.-Round Nose Pliers.
Figure 125.-Cutting Nippers.
The firepot shown in Figure 126 is a universal favorite
with the tinner and sheet metal worker. It is lined with
SHEET METAL WORKING TOOLS
firebrick and made in a most substantial manner. The
draft door is in two sections, which economizes fuel
Figure 127 shows a firepot so constructed that the ashes
fall in a pan beneath the coal and the fire is kept clear
and the draft good. It is light and may easily be carried
from place to place at the convenience of the workman.
Figure 126.-Cast Iron Firepot.
Figure 127.-Sheet Iron Firepot.
Figure 128.-Single Burner Gas Furnace.
Gas Furnaces.-Figure 128 illustrates a gas furnace for
heating soldering coppers. It is light in weight, consumes
but little gas, economizes time, and avoids dust and dirt.
By regulating the aperture through which the air passes
so that the flame has a blue appearance, the very hottest
flame produced by gas can be secured. It will burn either
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142 SHEET METAL WORKERS' MANUAL
natural or artificial gas. It has a single burner with a
sheet iron top.
A brick-lined double burner gas furnace is shown in
Figure 129. No air blowers being required, this furnace
is desirable for heating soldering coppers in the shop. It
is always ready for use and with the proper flow of gas
will produce a blue hot flame. It will burn either natural
or artificial gas.
Soldering Coppers.-Figure 130 shows the ordinary.
Figure 129.-Double Burner Gas Furnace.
Figure 130.-Square Point Soldering Copper.
Figure 131.-Roofing Copper.
Figure 132.-Bottom Copper.
soldering copper with square point, and a roofing copper
with shield and handle is seen in Figure 131. Figure 132
represents a bottom copper, and a hatchet copper with
swivel handle is shown in Figure 133.
A soldering copper handle is shown in Figure 134, and
two styles of solder scrapers, better known as plumbers'
scrapers, in Figures 135, 136. A useful roofing scraper is
shown in Figure 137.
The sheet metal working tools described in the fore-
SHEET METAL WORKING TOOLS 148
Figure 133.-Hatchet Copper.
Figure 1s3..-Hatchet copper-
Figure 134.--Soldering Copper Handle.
Figure 136.-Plumbers' Scraper.
Figure 137.-Roofing Scraper.
n ---- n~-----ar
1. Cox Furniture Co., Gainesville, Florida.
2. Examples of sheet metal roofing on N. W. 2nd Avenue, Gainesville,
3. Handcasting sheet lead, A Diderot Pictorial Encyclopedia of Trades
and Industries, pl. 192.
4. Tools for handcasting lead sheet, Ibid, pl. 194.
5. Lead foundry furnace and melting pot, Ibid, pl. 193.
6. Casting lead sheet, Ibid, pl. 195.
7. Hand forging copper sheet, Ibid, pl. 379.
8. Power forge for copper sheet, Ibid, pl. 144.
9. Nasmyth steam hammer forge, A History of Technology, Vol. 4, pl. 24.
10. Rolling mill, A Diderot Pictorial Encyclopedia of Trades and Industries,
11. Fatigue fracture hot rolled copper, Research Solves Problem of Stress
Failure in Sheet Copper Construction, p. 15.
12. Effect of shape, gauge and temper on copper's strength, Ibid, p. 26.
13. Helve power hammer forge, A History of Technology, Vol. 4, fig. 59.
14. Coinage press, Ibid, Vol. 3, Fig. 222.
15. Lead roofing on Ely Cathedral, The Care and Repair of Old Buildings,
16. Lead nosing and flashing detail, Stairbuilding, Ironwork, Roofing,
Superintendance and Contracts, p. 13-73.
17. Creep in lead roofing, The Care and Repair of Old Buildings, p. 98.
18. Dome St. Paul's Cathedral, London, A History of Technology, Vol. 3,
19. Dome Church of the Invalides, Paris, Ibid, p. 255.
20. Lead roofing drips, Stairbuilding, Ironwork, Roofing, Superintendance
and Contracts, p. 13-73.
21. Rolling mill for lead sheet, A Diderot Pictorial Encyclopedia of
Trades and Industries, pl. 196.
22. Acid etched lead roofing adjacent to lichen-covered slating, The
Care and Repair of Old Buildings, p. 99.
23. John Seagle Building, Gainesville, Florida.
24. Buckling of over-sized copper roofing sheet, The Care and Repair
of Old Buildings, p. 102.
25. Sheet preparation for flat locked copper roofing, Modern Sheet
Copper Practices, p. 17.
26. Bay window covering, Ibid, p. 49.
27. Bay window covering, Ibid, p. 49.
28. Bay window details, Architectural Construction, p. 165.
29. Leonardo's Pizzaria (copper roof), Gainesville, Florida.
30. Leonardo's Pizzaria (close-up of roof), Gainesville, Florida.
31. Leonardo's Pizzaria (detail of seam and outrigger cap), Gainesville,
32. Great Western Railway, Penzance Station, Iron Roofs, pl. 18.
33. Penzance Station, zinc roofing detail, Ibid, pl. 18.
34. Penzance Station, zinc roofing detail, Ibid, pl. 20.
35. Plating plant, Galvanizing and Tinning, p. 151.
36. Mechanical pickling equipment, Ibid, p. 45.
37. Magnified section of Sherardized steel, Ibid, p. 229.
38. Automatic galvanizing equipment similar to the Bayliss patent,
Ibid, p. 77.
39. Tinned shingle roof, S. E. 2nd Avenue, Gainesville, Florida.
40. Flat lock tinned sheet roof, Architectural Design, Roofing, Sheet
Metal Work and Mill Design, p. 56-49.
41. Tinning process, A Diderot Pictorial Encyclopedia of Trades and
Industries, pl. 149.
42. Iron roofing, Architectural Elements, pl. 1.
43. Corrugated iron roofing, Ibid, pl. 3.
44. Flat lock tinned roofing, Architectural Design, Roofing, Sheet
Metal Work and Mill Design, p. 54-51.
45. Nailed flat lock tinned roofing, Stair Building, Iron Work, Roofing,
Superintendance and Contracts, p. T3-43.
46. Iron roll roofing, Architectural Design, Roofing, Sheet Metal Work
and Mill Design, p. 54-25.
47. Corrugated iron roofing, Ibid, p. 54-41.
48. Flat lock seam roofing, Modern Sheet Copper Practices, p. 17.
49. Single and double locked flat seams, Research Solves Problem of
Stress Failure in Sheet Copper Construction, p. 33.
50. Standing seam roofing, Modern Sheet Copper Practices, p. 7.
51. Development of a standing seam, Research Solves Problem of Stress
Failure in Sheet Copper Construction, p. 33.
52. Variations of the standing seam, Architectural Design, Roofing,
Sheet Metal Work and Mill Design, p. 56-31.
53. Capped standing seams, Ibid, p. 56-32.
54. Pre-formed standing seam, Ibid, p. 56-37.
55. V-crimped roofing, Ibid, p. 56-38.
56. Hollow roll-joint roofing, Stair Building, Iron Work, Roofing,
Superintendance and Contracts, p. 13-57.
57. Lead nosing and drip details, Ibid, p. 13-73.
58. Redesign of lead roofing layout, The Care and Repair of Old Buildings,
59. Ribbed seam roofing, Modern Sheet Copper Practices, p. 13.
60. Development of ribbed seam, Stair Building, Iron Work, Roofing,
Superintendance and Contracts, p. 13-66.
61. Trough type ribbed seam, Ibid, p. 13-57.
62. Solid roll ribbed seam, Ibid, p. 13-58.
63. Interlocking pattern, Ibid, p. 13-70.
64. Sheet Metal Shingles, Architectural Design, Roofing, Sheet Metal
Work and Mill Design, p. 56-76.
65. Sheet metal tile for conical roofs, Stair Building, Iron Work, Roofing,
Superintendance and Contracts, p. 13-61.
66. Metal shingle interlocks, Architectural Design, Roofing, Sheet Metal
Work and Mill Design, p. 56-77.
67. Ridge-to eave shingles, Stair Building, Iron Work, Roofing,
Superintendance and Contracts, p. 13-55.
68. Ridge and hip finish, Architectural Design, Roofing, Sheet Metal
Work and Mill Design, p. 56-82, 83.
69. Valley finish, Ibid, p. 56-84.
70. Sheathing and underlayment, Ibid, p. 56-54.
71. Corrugated roofing without underlayment, Ibid, p. 56-42.
72. Wall hooks and roofing nails, Stair Building, Iron Work, Roofing,
Superintendance and Contracts, p.T3-40.
73. Ridge and valley finish, Instruction Manual for Sheet Metal Workers,
74. Sheet metal shears, Ibid, p. 29.
75. Double seaming on a stake, Ibid, p. 57.
76. Forming a seam with a cross-penn hammer, Ibid, p. 54.
77. Seaming tools, Ibid, p. 111.
78. Seaming operation, Ibid, p. 110.
79. Preparation for soldering, Ibid, p. 71.
80. Soldering operation, Ibid, p. 72.
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