Flat Roof Built Up Detail

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.

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. Others would treat even steeper pitches as flat roofs. 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.

The following outlines ways to build protect and reinforce your roof. Some carry warranties of up to 20 years approaching those for sloped roofing. Built up roofs have solved the low pitch roof problem for ages a challenge that asphalt shingles could never handle. Given that the specially selected insulation layer is loose laid it will require ballasting to guard against wind uplift or floating in wet conditions.

This flat roof system is still used in some residential applications because of its affordability and fire resistance. Fortunately modern materials for covering flat roofs have improved considerably over the past two decades. 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. 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.

As the roof is installed more and more layers are added to increase durability and longevity hence the name built up. The major difference between the warm flat roof and the cold flat roof has to do with the air flow between the roofing timbers known as joists that help to hold up the roof. Here we ll discuss types of flat roofing. When building a flat roof it is vital that a degree of falls is built into the construction to ensure rainwater run off.

Built up roofing. Tar and gravel 2.