Purpose Of Gravel On Flat Roof

A flat or low slope roof is often not a suitable surface for shingles or other roofing materials because moisture can t flow off them.

Purpose of gravel on flat roof.

Built up roofs or burs also called a tar and gravel roof is a well established and popular style of flat roof that is made up of alternating layers of roofing felt or fiberglass and asphalt that is applied with heat which combine to make a long lasting sturdy roofing system. It provides excellent protection against uv rays and is an attractive option for windows and decks that overlook the roof. Also a tar and gravel roof is very rugged and safe to walk on. The purpose of stone or gravel ballast on a flat roof published by justin on september 19 2019 september 19 2019 it is not unusual to find a gravel top coat on commercial roofing systems.

Gravel is an excellent fire retardant. Parts and composition of tar and gravel built up and flat roofing systems with a helpful tar and gravel roof construction diagram. Just enough slope to drain water but also flat enough to be a problem if not constructed properly. Of all the flat roofing options a tar and gravel roof is the most economical.

Gravel is used on flat roofs for two reasons. Of course flat roofs are not flat but have a very slight roof pitch of between 1 4 to 1 2 per foot. One is to act as ballast to weigh down the covering surface and help prevent it being blown off in high winds. A flat roof is a roof which is almost level in contrast to the many types of sloped roofs the slope of a roof is properly known as its pitch and flat roofs have up to approximately 10.

One solution to this is a built up or tar and gravel roof where many layers of hot asphalt or bitumen tar paper and a waterproof membrane are applied and then covered with gravel. On many flat roof low slope commercial buildings it s common to see gravel on top of the roof. Have you ever wondered why contractors install gravel on flat roofs. Built up roofing bur was the most common type of flat roof before modified bitumen and membrane roofing were developed.

A bottom layer or two of insulation board multiple intermediate layers of tar or asphalt alternated with layers of roofing felt and a top layer of gravel. The purpose of gravel on a flat roof. Flat or almost flat roofs can collect a tremendous amount of water especially if their outlets or downspouts become plugged with leaves and debris. A gravel or pea shingle on a roof serves two purposes.