| The roofing material selected depends on many factors. These include the cost, type of building, shape and pitch of the roof, climate, legal requirements, and insurance rates. Generally used materials are asphalt shingles, wood shingles, concrete tile, built-up roof, roll and metal roofing. |
| ASPHALT SHINGLES have a minimum recommended weight of 210 pounds for the square-butt and 215 pounds for the hexagonal type for each 100 feet of coverage. The square-butt triple shingle has three tabs. There are usually 27 strips in a bundle, and three bundles will cover 100 square feet, 1 square. The average life is 15 to 30 years. |
| WOOD SHINGLES are packed four bundles to the square. They are classified in grades. Grade # 1 must be 100% edge or vertical grain, 100% clear and 100% heartwood. None wider than 14 inches or narrower than 3 inches. Grade # 2 must be clear and free from blemishes for three fourths of their length as measured from the butts. Grade #3 must be 8 inches clear or better and may contain sapwood. Knot holes up to 3 inches in diameter are permitted in the upper half. |
| BUILT-UP roofs may have 3, 4, or 5 layers of roofer's felt, each mopped down with tar or asphalt, with the final surface coated witch asphalt or tar, or covered with a cap sheet of roll roofing. In some cases the final surface is mopped with gravel which becomes imbedded in the asphalt or tar. Built-up roofs are used extensively on`commercial buildings and are well suited for flat surfaces or areas with low pitch. Average life 12 to 25 years. |
| ROLL ROOFING comes in rolls, each roll containing one strip three feet wide and 36 feet long. Thus, the area contained in one roll is 108 square feet. But, since in the application of roll roofing, each strip must overlap the previously- laid strip, the net result is that one roll covers 100 square feet of area, or one square. There are twoweights in general use, namely 55 pounds and 90 pounds (per roll). The 55 pounds type has a smooth surface and is least expensive. The 90 pounds type may have a smooth surface or a slate surface (most expensive). |
| METAL ROOFING can be obtained in various types and grades to fit a particular need. Depending on grade the average life is from 20 to 50 years. |
| GALVANIZED CORRUGATED IRON is sold in sheets, varying in length from 6 feet to 12 feet. The width is usually 28 inches, which after overlap results in a net width coverage of 2 fee5t . The price varies according to the gauge (weight) of the metal. |
| CORRUGATED ALUMINUM is shaped in strips similar to corrugated iron and is applied in the same manner. |
| GALVANIZED STEEL, CHANNEL DRAIN, comes in long lengths and is relatively easily installed. Therefore, labor cost is held to minimum.
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| TIN roofing is the term applied tin-coated steel. The quality and price vary according to the weight of the metal. The material is cut to desired sizes and the sections are soldered together on the roof area. Proper application results in no leaks, even on a surface with practically no pitch. |
