How To Count Roof Layers

You can usually see the underside of plywood decking from the attic.

How to count roof layers.

Assuming this is a hip roof we multiply this by 1 1 which gives us roughly 18 squares or 1 800 square feet of the roof surface. There is a base wood shake layer and the asphalt shingle layers. He had gotten about 3 4 of the way through the job before the city shut them down. Outside of the u s a degree angle is typically used.

Porch roof extensions for hip roof porch extensions from an existing building wall you can use half the calculator results. R value of various materials. Minus ridge thickness to allow for ridge becoming pole plate roof peak will be slightly higher ridge thick must be same. Steep sloped roof products such as tile slate metal and shakes only allow one layer.

Measure the length and width of each portion of the roof multiply length by width for each plane and then add the planes together for the total square footage. For instance a 7 12 roof pitch means that the roof rises 7 inches for every 12 horizontal inches. My dad ended up landing the job. Asphalt shingles typically can have one more layer added over the top two roofs total.

For many years it was acceptable to put even the third layer. Here are the layers of a roof in order of application bottom to top. It appears to be 2 different colors for the asphalt shingle layers which made me think it was 2 asphalt shingle roofs. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials.

The roofer simply put plywood over a 5 layer roof and put a new layer of shingles over that. My dad has said to have done 7 layer tear offs. Needless to say we declined the job due to excessive cost and restructuring the roof. First layer was the original tin roof.

Find the square footage of the roof. For estimating purposes we also assume that there is a chimney a couple of dormers and two layers of old shingles that need to be torn off and removed before a new roof can be installed. Third layer was another layer of asphalt shingles. Enter the extension wall length into wall length and double the extension wall width then minus ridge thickness into the wall width entries.

For a very good introductory overview article on r value see r values over at the website of. If you are knowledgeable in being able to calculate from this view it would be hugely helpful. This gives us a 3d roof area of 1 625 sq ft. On most flat roofs such as epdm tpo or modified it is perfectly acceptable to two layers of roofing.

Finally the forth layer was wood shakes not kidding it was crazy. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches. It provides structure by tying the trusses and joists together. We have done some 5 layer tear offs redecks.

Decking most often made out of plywood this roof layer is installed over the framing in a typical roof install.