Shingles The roof sheathing, or decking, provides a strong, even surface to which some form of waterproofing material must be added to complete the roof. Asphalt Shingles In most parts of our country the popular material used for this purpose on residential homes is composition asphalt shingles. Asphalt shingles are manufactured in many sizes, shapes, and colours, the most common type being the 3-in-i, 300 mm x 900 mm strip shingle. This type of shingle has a heavy felt base in which is embedded fire-resistant rock granules. Low-Slope Asphalt Shingles. For roofs with a slope ratio as low as 1:6, special low-slope shingles measuring 450 mm x 900 mm are manufactured. Since the amount of shingle (usually 130 mm) exposed to the weather is the same as with the 300 mm x 900 mm standard shingle, low-slope shingles will provide 3 thicknesses of shingle over the entire roof. Realted Links Doityourself.com