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Affordable Roofing Service
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Underlayments perform to prevent wind driven rain or water form infiltrating under shingles. The most common type used in residential homes is a black, asphalt-saturated felt paper. An “organic” underlayment has a cellulose base as opposed to a fiberglass substrate. There are two thicknesses, 15 pound and 30 pound with the thirty-pound being more thicker and stiff.
4 to 12 inch pitch sloped roofs (inches of slope per foot distance, 12 pitch is a 90 degree or right angle) should have an overlap of at least 2 inches. There are other variations of underlayments such as rubberized asphalt and polymer-modified bitumen. Rubberized asphalt typically have adhesive on one side with a peel off membrane making it self-adhering. Polymer-modified bitumen gives it a plastic-like or rubber type of properties.