Flat Roof Layers

Bur systems are redundant meaning if one layer breaks down multiple remaining layers provide immediate protection.

Flat roof layers.

It s all about the money. Modified bitumen is installed in multiple layers multi ply roof each of which is torched to the surface below at every turn of the roll. Tar and gravel 2. Of course flat roofs are not flat but have a very slight roof pitch of between 1 4 to 1 2 per foot.

Adhesive metal straps or gravel are used to secure the rubber roof systems. But now flat roofs often are constructed with fewer layers because of improved waterproofing technology. Just enough slope to drain water but also flat enough to be a problem if not constructed properly. Modified bitumen an asphalt based multi ply flat roofing system is considered a modern take on its close cousin bur or built up roof.

The slope of a roof is properly known as its pitch and flat roofs have up to approximately 10. Orient the spade at a 30 to 40 degree angle to the roof and start thrusting a spot in the middle of the roof repeatedly. The number of plies on a roof implies the number of layers i e. 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.

Why would you want to recover vs tear off. Drawbacks include potential leakage at the seams or from product shrinkage. As the roof is installed more and more layers are added to increase durability and longevity hence the name built up. Flat roofs are hard to replace some observers suggest it s harder to replace a flat roof than a traditional pitched shingle roof because of the labor required to remove its layers especially on older flat roofs.

Four plies denotes a four layer flat roof membrane system. On the plus side. Flat roofs are an ancient form mostly used in arid climates and allow the roof space to be used as a living space or a living roof. A flat roof is a roof which is almost level in contrast to the many types of sloped roofs.

Built up roofing bur was the most common type of flat roof before modified bitumen and membrane roofing were developed. Rubber is waterproof and is relatively easy to install. However in almost all areas it is not acceptable to install more than two layers of roofing on any commercial building. 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.

Plies are the layers of felts fabrics and mats that make up roofs. Bur consists of many layers.