TECHNICAL INFORMATION ON BUILDING MATERIALS

FOR USE IN THE DESIGN OF LOW-COST HOUSING

*******

THE NATIONAL BUREAU OF STANDARDS

UNITED STATES DEPARTMENT OF COMMERCE

WASHINGTON, D. C.

TIM - 41

December 29, 1956

ROOFING TIN (TEMPLATE) FOR HOUSE CONSTRUCTION

The principal use of terneplate in house construction is for roofing.

It is also used for flashing, furnace casing and occasionally for heating

and ventilating ducts.

Most ferrous metal roofs are made of terneplate. This is particularly

true if the roof is fiat or nearly so. Galvanized sheets, however, are

1 occasionally used for roofs having a steep pitch and under most conditions,

where so used, give greater protection from atmospheric corrosion. (See

I TIBM - 17 "Atmospheric Corrosion of Galvanized Ferrous Sheet Metals")'.^

P Some advantages of terneplate over galvanized roofing sheets are* greater

}

! pliability, possibility of making stronger soldered .joints, and increased

durability of ordinary paint coats (See TIBM - 28 "Painting of Ferrous

Metals"?, as terneplate has exceptionally good "paint-holding" properties.

Terneplate is made by passing annealed and pickled steel or iron sheets

(See TIBM - 42 "Black and Galvanized Sheets in House Construction") through

E a bath of molten lead-tin alloy (usually 75 percent lead and 25 percent tin).

I By this means, the sheet is covered on both sides with a reasonably uniform

I coating of lead-tin alloy. To produce a good grade of terneplate, the black

\ sheets before coating should be free from blisters, slivers, scale, lamina-

[ tions, open seams, dirt and grease spots, ragged edges, hcles, pickling

patches, stains, burnt edges, brittleness and internal or surface defects

I which would impair their use for terneplate manufacture. The finished terneI plate sheets should also be free from the above mentioned defects, and have

i no bare or imperfectly coated spots, deep scratches or heavy list edges.

Open-hearth or Bessemer steel or open-hearth iron, with or without

added copper for increasing atmospheric corrosion resistance, (See TIBM - 1C

"Atmospheric Corrosion of Ferrous Metals") is used to make terneplate sheets.

I The sheets are cold-rolled, double-annealed and double-pickled, making them

soft and easily workable, having a surface that will take a smooth coating,

1 Copies of all TIBM releases mentioned in this paper may be obtained

from the National Bureau of Standards, Washington, D. C. (Free)

features which are important in the manufacture of terneplate. Very pure

grades of tin and lead should he used in making the 75-25 coating alloy,

Tin plus lead in the coating must he not less than 33 percent of the coating (exclusive of iron from the basis metal, which forms an alloy with

the coating that provides the bond between them).

Terneplate is usually furnished for builders in Grades "IC" and "IX",

the latter being the heavier gage, with about 25 percent difference in

weight. The significance of those trade designations is shown by the data

in Table I, which gives the weight of the black sheets for "IC" and "IX"

terne, in ounces per square foot or pounds per base box, and the corresponding

weights of the coated sheets for coating weights, varying from 2 to 40 pounds

per box. The 25-pound terne sheet is commonly used for roofing. A "box" of

terneplate consists of 112 sheets, 20 x 28 inches, which is the equivalent

of 62,729 square inches or 435.56 square feet of sheet. It will be observed

that Table I also contains a column expressing the weight of coating in ounces per square foot of sheet. This is the nominal weight of coating and

normally varies somewhat on different parts of a sheet, but no area should

have a coating less than 75 percent of that specified in Table I. The weights

of terne sheets should be within the limits set in this table.

Terne sheets should withstand, without fracture, double-seaming as well

as bending through 180° and flattening down with a wooden mallet on a wooden

block, both tests being made with and across the direction of rolling.

Terne roofing sheets are nearly always supplied with one side painted.

This is to be used as the under side in roof construction. The upper side

should be painted without delay. Rusting may proceed rapidly out of doors,

especially at places where the coating has been damaged (See TIBM - 17

"Atmospheric Corrosion of Galvanized Ferrous Sheet Metals"). The paint coat

should be renewed as often as needed, but care should be taken not to build

the coating up too thick. Useful information regarding such painting is con- tained in National Bureau of Standards Letter Circular No. 422 "The Painting

of Structural Metal (Steel, Galvanized Metal, Tin Plate and Copper ]."^ Many

other item3 of interest to users or purchasers of terneplate are given in

Federal Specification Q.Q-T-201, "Terneplate (Roofing Tin)."

1

May be obtained from the National Bureau of Standards, Washington, P. C«

(Free)

2

May be obtained from the Superintendent of Pocuments, Washington, P. C.

(Price 5 cents)'

2
table I - DATA for commercial terneplate

trade

SYMBOL

' WEIGHT OF COATING, IN POUNDS PER BOX

WE I GHT OF BLACK ' SHEETS

after

PICKLING

» * • • « 8 : is : 20 *25 i 30 : 40

WEIGHT - OF COATING/ IN OUNCES PER SQUARE FOOT OF SHEET

r

1—1

s 1 s 0.2939 ! 0.5510 : 0.7347 : 0.9164 1 1.1020 1 1.4694

WEIGHT OF FINISHED SHEETS

C crz"/ ' vur/-

sq ft:box

137/ ruff"/:'02 /

rC87loi/^ :lb/:oz / :lb

/

to i

/

:lb /:oz / ror so ft:box:sq ft:boX:sq ft:box:sq ft:box:sq ft:box:sq ft:bo

'minimum. . 7

.

00 ; 1 9 1 7.29: 199 7.55:206 7.73 2li: 7.92 216 : 8. 10 : 221 : 8 . 47:231

IC | NOMINAL.

.

8.00:218 8.29:226 3.55:233 8.73 238: 8.92 243: 9. 10:2485 9.475258

• • * • MAXIMUM.

.

9.00:245 9.29:253 9.55:260 9.73 265! 9.92 270 ! 10. 10:275: 10.47:285

'minimum.. 9.00:245 9.29*253 9.555260 9.73 2655 9.92 270: 10. 10:275: 10.475285

IX NOMINAL.

.

10.00:272 10.29:280 10.55 5287 10.73 292: 10.92 297 : 1

1

. 10 : 302 : 1

1

. 47:312 • • t MAXIMUM.

.

1

1

. 00:299 1 1 .295307 11.55:314 11.73 3 1 9 ! 1 1 . 92

• 324 : 12 . 10 : 329 : 12 . 47:339t • • •

* TOTAL FOR BOTH SIDES

“ 3 “
TECHNICAL INFORMATION ON BUILDING MATERIALS

FOR USE IN THE DESIGN OF LOW-COST HOUSING

TIM - 41

*******

THE NATIONAL BUREAU OF STANDARDS

UNITED STATES DEPARTMENT OF COMMERCE

WASHINGTON, D. C.

December 20 , 1956

ROOFING TIN (TERNEPLATE) FOR HOUSE CONSTRUCTION

The principal use of terneplate in house construction is for roofing.

It is also vised for flashing, furnace casing and occasionally for heating

and ventilating ducts.

Most ferrous metal roof3 are made of terneplate. Thin is particularly

true if the roof is flat cr nearly so. Galvanized sheets, however, are occasionally used for roofs having a steep pitch and under most conditions,

where so used, give greater protection from atmospheric corrosion. (See

TI3M - 17 ’’Atmospheric Corrosion of Galvanized Ferrous Sheet Metals’1 )'* Some advantages of terneplate over galvanized roofing sheets are: greater

pliability, possibility of making stronger seldered .joints, and increased

durahility of ordinary paint coats (See TIBM - 28 "Painting of Ferrous

Metals" ' , as terneplate has exceptionally good "paint -holding" properties.

Terneplate is male "by passing annealed and pickled steel or iron sheets

(See TIBM - 42 "Black and Galvanized Sheets in Hruse Construction")) through

q. "bath of molten lead-tin alloy (usually 75 percent lead and 25 percent tin).

By this means, the sheet is covered on "both sides with a reasonably uniform

coating of lead-tin alloy. To produce a good grade of terneplate, the Black

sheets Before coating should Be free from Blisters, slivers, scale, laminations, open seams, dirt and grease spots, ragged edges, holes, pickling

patches, stains, Burnt edges, Brittleness and internal or surface defects

which would impair their use for terneplate manufacture. The finished terneplate sheets should also Be free from the above mentioned defects, and have

n© "bare or imperfectly coated spots, deep scratches or heavy list edges.

Open-hearth or Bessemer steel or ©pen-hearth iron, with or without

added copper for increasing atmospheric corrosion resistance, (See TIBM - 10

"Atmospheric Corrosion of Ferrous Metals") is used to make terneplate sheets.

Tfc.e sheets are cold-rolled, double-annealed and douBle-pickled, making them

soft and easily workable, having a surface that will take a smooth coating,

1 Copies of all TIBM releases mentioned in this paper may Be obtained

from the National Bureau of Standards, Washington, D. C. (Free)
.

-

K;

.

‘ '

I

.

; ;

l

•

- B

!

!
features which are important in the manufacture of terneplate. Very pure

grates of tin and leal should he used in making the 75-25 coating alloy,

Tin plus lead in the coating must he not less than 33 percent of the coating [exclusive of iron from the basis metal, which forms an alloy with

the coating that provides the bond between them).

Terneplate is usually furnished for builders in Grades "IC" and "IX"

,

the latter being the heavier gage, with about 25 percent difference in

weight. The significance of those trade designations is shown by the data

in Table I, which gives the weight of the black sheets for "IC" and "IX"

terne, in ounces per square foot or pounds per base box, and the corresponding

weights of the coated sheets for coating weights, varying from 2 to 40 pounds

per box. The 25-pound terne sheet is commonly used for roofing. A ’’box" of

terneplate consists of 112 sheets, 20 x 22 inches, which is the equivalent

of 62,729 square inches or 435.56 square feet of sheet. It will be observed

that Table I also contains a column expressing the weight of coating in ounces per square foot of sheet. This is the nominal w'eight of coating and

normally varies somewhat on different parts of a sheet, but no area should

have a coating less than 75 percent of that specified in Table I. The weights

of terne sheets should be within the limits set in this table.

Terne sheets should withstand, without fracture, double-seaming as well

as bending through 180° and flattening down with a wooden mallet on a wooden

block, both tests being made with and across the direction of rolling.

Terne roofing sheets are nearly always supplied with one side painted.

This is to be used as the under side in roof construction. Tho upper side

should be painted without delay. Easting may proceed rapidly out of doors,

especially at places where the coating has been damaged (See TIBM - 17

’’Atmospheric Corrosion of Galvanized Ferrous Sheet Metals"). The paint coat

should be renewed as often as needed, but care should be taken not to build

the coating up too thick. Useful information regarding such painting is con- tained in National Bureau of Standards Letter Circular No. 422 "The Tainting

of Structural Metal (Steel, Galvanized Metal, Tin Plate and Copper Many

other items of interest to users or purchasers of terneplate are given in

Federal Specification Q,Q-T“201, "Terneplate (Roofing Tin).’’

1

May be obtained from the National EUreau of Standards, Washington, D. C.

(Free)

2

May be obtained from the Superintendent of Tocuments, Washington, T. C.

(Price 5 cents)

2
TABLE I - DATA for commercial terneplate

TRADE SYMBOL

WE I GHT OF BLACK

SHEETS

AFTER

PICKLING

WEIGHT OF COATING, IN POUNDS PER BOX

r-rar

ft: 8 ox

8 20 25 30 40

W E I G HT OF COAT 1 NG , * IN OUNCES PER SQUARE FOOT OF SH E E T 0.2939 : 0.5510 ; 0.7347 : 0.9104 ! 1020 I . 4694

^7 Tr3

o ft:box7

'mini mum

.

. 7.00: l

9

7.29: 199

• 7.55:206 7 . 73:21 1 : 7.92 216 : S. 10:221

IC NOMINAL.

.

8,00:218 8.29:226 8.55:233 8.73:238: 8.92

• • 243 : 9. 10*240

MAXIMUM.. 9.00:245 9.29:253 9.55:260

k 9.73:265: 9.92

• • 270 1 10. |0:275^

• •

• • 'minimum.

.

9.001245 9.29*253

« 9.555260• • 9.73:265: 9.92 270: 10. 10:275

IX NOMINAL. . 10.00:272 10.29*280 I0.55!2B7 10.73:292: 10.92

• • 297: I I

.

10:302

MAXIMUM. . 1 1 .00:299 1 1 .29:307 1 1 .555314 I 1 .73:319: 1 1 *92

• 1 • • 324: 12. 10:329» •

t 1

TJZf—TOST

SQ FT IBOX

WEIGHT OF FINISHED SHEETS

0T7 TlB” sq ft:bo>

3*7

SQ FT BOX

/~TLH/

ft:boX

oz/ tub/

sq ft:box

8.47:231

9.47:258

I0.47t285

10.47:285

I 1.47:312

12.47:339

* TOTAL FOR BOTH SIDES

- 3