Two Layer Roof Structure

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.

Two layer roof structure. Adding a second layer could compromise the structure of your roof. Richards also estimates that the homeowner saves at least 1 000 in costs associated with removing and properly disposing of the existing shingles. First of all multiple layers of shingles simply means layering a new asphalt shingle roof on top of the old one rather than stripping the roof completely to expose the sheathing and replacing it with new shingles. The homeowner will have two layers of shingles protecting the roof and the home is less likely to have ice dams he says.

For example towns in climates with heavy hailstorm activity or significant ice dam problems may not allow multiple roofing layers. It provides structure by tying the trusses and joists together. If you don t tear off the old layer you can t examine the decking. We are really talking about two different issues.

Ice water barrier this self adhering water proof and self sealing membrane is applied to the roof deck. A second layer of shingles only complicates the job when a roofer is trying to fix a leak. Five best practices reasons for using roofing felt underlayment. You can usually see the underside of plywood decking from the attic.

When a buyer is purchasing a home their homeowner s insurance carrier will inquire about the age of the roof and the number of layers. In most areas building codes allow for up to two layers of shingles installed on a roof. Multiple layers of composition roofing and composition over a wood shingle shake roof. The first course starts with an extra 1 2 wide run.

On 4 12 or greater slopes the balance of the roof shall be one layer of 15 felt. Pros to overlaying a shingle roof. Often there is a problem with the first layer of shingles that was not apparent before the second layer was added. Disadvantages to a roof recover.

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. So anywhere along the gable end that you can see the felt you ll see two layers. If two layers already exist you ll need to remove the old layers before installing a new layer of shingles. Local codes might not allow re roofing.

Most building codes allow this but is it a good idea. A re roof might not look good on an inspection report. For a second layer to be as good as a roof tear off you would have to have sound decking no leaks and a roof with no sidewalls where flashing is needed in order to tie the tiles in to the exterior walls. Most often made out of plywood this roof layer is installed over the framing in a typical roof install.