Flat Roof Felt Systems

1 built up torchon felt system.

Flat roof felt systems.

This type of flat roofing felt has been in use for decades and is still used today. The hot applied asphalt or coal tar pitch blends with the bitumen soaked roof felt and creates a monolithic roof membrane. This could mean flat roofs may not raise the same red flags they used to. However it wasn t particularly long lasting or durable so torch on felt was created.

Built up roofing bur was the most common type of flat roof before modified bitumen and membrane roofing were developed. Light weight shed roofing felt is not suitable for flat roof construction. Felt is laid on a flat roof to help keep the roofing system waterproof. Built up roofs are installed using several layers of a special type of roofing felt that has been asphalt impregnated and embedded in bitumen applied with a hot mop.

Check to ensure the roof is in good enough condition to walk over. Here are simple steps to get you started. The underlying deck must be constructed of moisture tolerant materials such as 18mm wbp plywood or suitable chipboard stirling board on treated timber joists. Step 1 prep work.

Felt roofing also known as tar paper is traditionally installed using hot bitumen to create a secure bond between the roof and the felt. In short any roof covering that can make a flat roof waterproof in one layer unlike roofing felt with its 3 layer system for instance. Bur consists of many layers. Roofing felt is one of the oldest available options and advances made in the past decade or so have begun to move more towards the torch on approach.

Make sure the roof is clean dry and that all nail heads are flush with the deck. 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. But now flat roofs often are constructed with fewer layers because of improved waterproofing technology. 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.

Pros and cons for flat roof materials all three types of flat roofing cost 250 to 350 per square 100 square feet but prices vary according to region and size of the roof. Roofing felt is one of the more popular and traditional methods of creating a flat roof. While laying felt is not an easy job it can be done by anyone who has the patience to deal with it. Flat roofs are hard to replace.

This can include epdm rubber and fibreglass talked about above but commonly especially in the trade and in this article it refers to pvc tpo tpe and pib. Layers of bitumen felt are heat welded onto each other to form an impenetrable barrier.