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1945 Theatre Catalog, 4th Edition, Page 188 (166)

1945 Theatre Catalog, 4th Edition
1945 Theatre Catalog
1945 Theatre Catalog, 4th Edition, Page 188
Page 188

1945 Theatre Catalog, 4th Edition, Page 188

Know your roof. owner does not know he has one until it

leaks. The roof is an important part of

An Introduction to the Knowledge of Roofs

Covering, Flashing, Drainage of Roofs Are Three Important Details to Consider

Many a theatre

The Barren Division, Allied Chemical and Dye Corporaliou

By J. D. STEBBINS expense. Material used in the roof covering should be selected to meet the de tailed requirements of the job. The

your plant and needs your attention and care. Do not wait until the water is running down your patronsl necks or the plaster starts peeling from the ceiling. Remember the old saying, "A stitch in timefy


Roofs, which give no trouble or need no repairs, start on the drafting board in

Panama or Blunt Sprcmcmon Pncn

{out Puts or buun. . Suc'mcmon Yur

FOUL Huvr Mommas or BIRRLTT SPLcchTION Pircu

FOR FLAT ROOFS (above), or on those with an incline not exceeding 2 inches to I foot, this drawing gives the suggested construction plan of the Barrett Division of the Allied Chemical and Dye Corporation. To be used over a deck of poured concrete or gypsum, Type AA is of 4-ply construction, and, when installed according to the company's specifications, carries a 20-year guarantee. Over the roof deck which has been rid of dirt and loose material, and when dry, smooth, and firm, a "binder" layer of pitch is placed, and then four plies of felt are laid down, on top of each going a mapping of pitch, and over all, a final layer of pitch into which gravel or slag, from M: to 5/3 inch in size, is embedded.Z171 7' i e

4 to LAT Roar

the architect's ofiice. The roof structure should be so designed as to allow for the application of a water-proof covering which will give the longest life. Everything in connection with the selection of the roof and its application should be carefully considered anddetailed, in order to insure proper functioning and freedom from annoying and costly repair

FOR STEEP ROOFS (below), on those with inclines over 3 inches, but not exceeding 9 inches, to l foot, this drawing shows the method of construction suggested by the Barrett Division. It may be laid over a deck of either poured concrete or gypsum. First, the surface of the roof deck is given a priming coat, which is allowed to dry for not less than 6 hours before the application of the actual roofing. Then the entire surface is coated with asphalt roofing. Then the entire surface is coated with asphalt or S. l. S. cement. For cold application, two plies of I5-pound felt are laid over the entire surface of the roof at right angles to the incline. A coating of S.I.S. cement is, of course, applied between the plies.



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roofing contractor should be chosen for his skill and responsibility and for his general experience with the particular type of work involved. Finally, you should insist on securing a satisfactory guarantee covering maintenance of the job.

If your building is designed for a flat roof, you are fortunate. The more complicated the roof, with fiat and steep surfaces adjoiningwr the more the roof is cluttered up with unnecessary structures*the more difiicult it. will be to keep it tight. Keep your roof as simple as possible*keep it free of projections or appurtenances that serve no useful purpose. Keep it clean and free of foreign or loose material.


The probabilities are that your roof is -or will b%0f the built-up type. Most roofing of this type is built of either asphalt or coal-tar products, or both. It is well to know the difference between the two and where the use of each is indicated. Non-technically, asphalt is derived from the distillation of petroleum and is principally produced by the oil renneries. Coal-tar pitch is obtained from the distillation of coal-tar, which is a by-product in the coking of bituminous coal.

In the application of roofs on fiat or nearly flat surfaces, coal-tar pitch and felt saturated with coal-tar should always be used. Combined, they provide the membrane of the roof covering-the pitch comprising the water-proofing element and the felt the binder that holds the water-proofing in place. Where the incline of' a roof is greater than two inches to the foot, either asphalt or special types of roofing pitch may be used. In all cases the roof should be finished with a top protective surfacing of mineral. Crushed slag or gravel is most commonly used on fiat areas, and mineral granules on steep areas. The mineral surfacing has a most important function in preserving the roof. It screens out the actinicwr ultraviolet*rays of the sun and thereby prevents or retards drying out of the bitumen. It provides protection against flying embers and generally serves the same purpose as paint on structural steel. All standard roofs are tested by the National Board of Fire Underwriters. Fire ratings, designated as ttA," "B," or to," are given to these roof coverings, based on their ability to resist the spread of fire. Before selecting a roof, it is well to check with the roofer, or carrier of your fire insurance, to be sure that the roof does not interfere with your obtaining the lowest available rate.

1945 Theatre Catalog, 4th Edition, Page 188