Flat Roof Built Up Detail

This flat roof system is still used in some residential applications because of its affordability and fire resistance.

Flat roof built up detail.

Built up roofs are manufactured using built up layers of either tar saturated paper and liquid tar with gravel asphalt rolled asphalt or modified bitumen. In the warm flat roof construction there is insulation packed into every possible space where air can flow. Built up roofing bur this multi layer roof design is a proven system that has been around for generations. When building a flat roof it is vital that a degree of falls is built into the construction to ensure rainwater run off.

Here we ll discuss types of flat roofing. Fortunately modern materials for covering flat roofs have improved considerably over the past two decades. The definition of a flat roof according to bs 6229 is having a pitch less than 10 o to the horizontal however some in the industry would consider up to 15 o as their definition of a flat roof. Going back about 120 years the grandfather of flat roofs is the built up roof or bur.

Built up roofing bur most often used in commercial and industrial applications this flat roof system contains layers of waterproof membrane such as a treated fiberglass basemat tar and gravel to seal the flat roof surface. Others would treat even steeper pitches as flat roofs. Given that the specially selected insulation layer is loose laid it will require ballasting to guard against wind uplift or floating in wet conditions. A further benefit of this type of flat roof build up is that the waterproofing layer is hidden and thereby protected from the effects of solar gain.

Some carry warranties of up to 20 years approaching those for sloped roofing. Tar and gravel 2. As the roof is installed more and more layers are added to increase durability and longevity hence the name built up. The following outlines ways to build protect and reinforce your roof.

Built up roofs have solved the low pitch roof problem for ages a challenge that asphalt shingles could never handle. If you build and flash one right and keep it clean a good flat roof won t leak says toh general contractor tom silva who had seven different flat roofs.