Built-up Roofs & Roll Roofing
Homes with flat or low-sloping roofs usually have a built-up roof surface, also called a tar-and-gravel roof.
Sheds, garages, and other out-buildings are sometimes roofed with asphalt roll roofing.
A built-up roof consists of several layers of roofing felt, each coated with hot or cold-mopped asphalt. The top layer is surfaced with crushed gravel or rock. These roofs generally last from 10 to 20 years, depending on the sun’s intensity.
Asphalt roll roofing, made in the same way as asphalt shingles (page 31), has a lifetime of 5 to 15 years. Sometimes, roll roofing of a matching color is used to cover the valleys of an asphalt shingle roof.
Leaks in a flat roof are usually easy to locatethey tend to be directly above the wet area on the ceiling.
Leaks may develop at flashings (page 34) or where wind has blown the gravel away to expose the surface. Leaks are also likely where weather and wear have caused blistered asphalt, sepa-rations between the roof surface and the drip edge, curling or split roofing felt that’s exposed, and cracks or holes in the roof material.
Repairs are the same for both built-up and roll roofing. Fill in any cracks with roofing cement. If you’re re-pairing a blister or small hole (see be-low), cut the patch you need from either a piece of roll roofing or an asphalt shin-gle. Use galvanized roofing nails to secure the patch. Any hole larger than a square foot should be patched by a professional roofer.
If your roof is beyond repair and must be replaced, it’s best to call in a professional. Resurfacing a flat roof
with layers of roofing felt and hot-mopped asphalt is beyond the scope of most homeowners because of the
processes and equipment involved; moreover, working with hot molten asphalt is a messy difficult, and even dangerous job.
Repairing A Blister
Patching A Hole
