Two Layers Of Felt On Roof

The key to weatherproofing your flat roof is adding a total of 3 layers.

Two layers of felt on roof.

Most often made out of plywood this roof layer is installed over the framing in a typical roof install. So anywhere along the gable end that you can see the felt you ll see two layers. This will help the two layers adhere to each other. It provides backup protection in the event of ice or water damage.

Five best practices reasons for using roofing felt underlayment. In northern climates ice or snow dams are another common. The first course starts with an extra 1 2 wide run. You will follow the same process as in step 2 for the last layer.

Though the requirement is 2 layers 15 felt in my area northern california the roofers spec 30 whether for 2 layer low slope or 1 layer normal high slope. Wind driven rain or snow can trap water under your shingles putting your roof deck and inner residence at risk of moisture. Saving on the initial shingle installation doesn t solve the long term cost of adding a second layer of shingles. 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.

Add the second layer. Thus you will repeat the earlier steps. Here are the layers of a roof in order of application bottom to top. Before adding the second layer though spread a thin layer of adhesive on the first layer using your trowel.

Apply another layer of adhesive to the top for maximum waterproofing. It didn t come with any underlay but i have worked out i could felt the roof twice with the cap sheet felt they have supplied. For decades roofers have fitted a layer of felt over a roof s sheathing or roof deck before installing shingles. Assuming your roofing contractor is using standard 36 wide 15 roofing felt double coverage means that each layer of felt put down across the roof laps 19 over the upper half of the previous course.

Cover the edges of the roof with strips of felt before laying out the final layer. Why use roofing felt paper. You can cover the surface of the felt with gravel for added strength. Roofing felt offers an additional layer of protection against the elements.

Two layers of shingles trap more heat which in turn damages the shingles and shortens the life span of the roof. I am aware of the best practise of at least one layer of underlay nailed to the deck before a cap sheet is glued to the top with cold adhesive. On 4 12 or greater slopes the balance of the roof shall be one layer of 15 felt.