Gaf Torchdown Overtop An Existing One Layer Roof

Depending on your roofing systems design one of these membranes might be a better choice than the other.

Gaf torchdown overtop an existing one layer roof.

A two layer system is made up of one base layer and one torch down layer. Plus learn the advantages and disadvantages of a torch down roof system. Single ply membranes such as pvc epdm tpo or torchdown also known modified bitumen are the most common low slope and flat roofing materials. There are many choices and material types you can use on your flat roofing system in seattle.

Torch down roofs are composed of two or more layers of a modified asphalt membrane applied with an open flame torch. The installed cost of ruberoid torch granule membrane is less than most single ply systems on the market today. Typical system guarantees available for up to 15 years. Installed roof designs weigh less than 2 pounds per square foot ruberoid torch granule membrane polyester mat core allows it to resist splits.

Installing new roof shingles over old effectively doubles the weight of the roofing so you have to make sure your roof structure can handle the extra load. How to install a roof over an existing roof. Two layer systems tend to last approximately 15 years while three layer torch down roofing can last 20 years or longer. Three layer systems have a base a smooth torch down layer and a torch down layer with a granular surface.

What is a torchdown roofing system. Some roofers install a layer of waterproof shingle underlayment wsu over the existing shingles at the eave end as would be done for a roof laid on bare sheathing. However installing new flashings including special drip edge flashings made for reroofing will ensure a tight seal and a long life. Select system constructions available with up to 20 year guarantee coverage 1.

Ruberoid torch smooth membrane is backed by gaf a company with over 130 years in the roofing business. Advantages of three layer torch down roofing. A three layer torch down roof features the same base and cap sheets as well as an additional cap sheet with a granulated surface. Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option.

The membrane is available with a smooth surface. Discover the various components of a torch down roof and the materials used to manufacture it. Its core is a strong resilient non woven polyester mat that is coated with weather resistant app polymer modified asphalt. There are two different types of torch down roofing systems.

This provides added protection against ice dams. Chances are your roof structure was designed for a dead load of one layer of shingles plus extra for snow and a safety margin.