Most houses with flat or nearly flat roofs are topped with built up roofing or tar and gravel roofing made from fiberglass based asphalt sheeting that is applied in layers with hot bitumen tar mopped on between each layer.
Tar and gravel roof construction.
No more than 3 inches of rise for every 12 inches of length.
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.
Tar and gravel roofing is meant to be installed on buildings that have flat or low slope roofs i e.
Used in the united states for more than 100 years tar roofs were traditionally six ply meaning that they had six layers of roofing material.
The average roofing installation price for a tar gravel built up roof costs anywhere between 3 750 to 6 750 depending on the slope pitch and size of your roof.
Foot or 250 to 400 per square installed on a standard sized single story home.
A tar and gravel roof or built up roofing consists of several layers of waterproof material alternated with hot tar and a surface layer of mineral aggregate often smooth river stone.