Flat Roof How Many Layers Of Felt

Why use a felt underlay roof.

Flat roof how many layers of felt.

There needs to be an overlap in the felt to help increase the water tight quality. You wan walk over the roof to remove any air bubbles that may form. You will be placing the second layer of felt over this. It must be installed the full length of all valleys.

On 4 12 or greater slopes the balance of the roof shall be one layer of 15 felt. Add the second layer. Overlay a second layer of felt 2 to 3 inches and fasten it through the overlay so it secures the top of the felt underneath. A layer of roof felt is laid down and hot asphalt is mopped overtop repeat for two to four layers called plies repair involves reapplication of original materials and or roofing cement to fix cracks or leaks.

These thick layers of roofing felt are installed by heating the back of the felt with a butane torch and then carefully applying it to the roof. A third layer of felt needs to be placed. Generally felt underlay roof works by combining two or three layers of material together to make an impenetrable barrier that is then coated with a waterproof finishing material to further protect the felt. The key to weatherproofing your flat roof is adding a total of 3 layers.

Paint a thin layer of adhesive over the first felt layer. Thus you will repeat the earlier steps. This will help the two layers adhere to each other. These applications are ideal for flat roofs or protective surfaces under roof level decks.

Felt roofing is a very common material used on flat roofs such as garages garden sheds and on extensions. Before adding the second layer though spread a thin layer of adhesive on the first layer using your trowel. 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. Snap a chalk line the.

Align this layer with the bottom of the roof. However in almost all areas it is not acceptable to install more than two layers of roofing on any commercial building. On roof slopes of 2 12 to 4 12 the remainder of the roof shall be two layers of 15 felt applied in shingle fashion or 1 layer of ice dam protection. There are many different types of flat roofing systems available each one with their own pros and cons.

For many years it was acceptable to put even the third layer. Some roofing felts are actually glued down.