2 Layers Of Roof Rafters

When framing a roof figure 7 2 carpenters must be familiar with commonly used roofing terms figures 7 3 and 7 4.

2 layers of roof rafters. I ve done roof venting with a carbide chainsaw and an extra layer of plywood would make no difference the saw eats right thru multiple layers of asphalt metal roofing whatever. They vary in size depending on length and spacing. It is very easy to cut completely thru a 2x12 rafter and not know it. They are inclined members spaced from 16 to 48 inches apart.

When you cut the rafters you ll need to make 3 separate cuts. Epdm roof membrane 90 mil fully adhered membrane only 0 56 lbs. The most common rafter spacing is 24 inches and 5 8 inch plywood is recommended for that. This is especially true if you ve overlayed your new shingles on top of warped shingles.

Rafters rafters make up the main framework of all roofs. Get some other roofing companies minimum of 2 to inspect the roof and give you an assessment of the roof deck shingle condition and estimate to replace the roof deck shingles. Epdm roof membrane 60 mil fully adhered membrane only 0 47 lbs. Having multiple layers of shingles is going to make your roof hotter because the heat gets trapped between the layers which could mean premature aging of the shingles.

Allow for ridge thickness when determining rafter run to outer wall. For rafters spaced 20 or more inches apart 1 2 or 5 8 inch plywood is recommended. Ice and water shield self adhering. See rafter run to outer wall calculator below.

Gypsum roof board 1 2 inch thick. Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through. My house has 1 2 cdx over 7 8 fir skip sheathing. This synthetic layer which replaces felt paper covers the entire roof deck and is the second line of defense against leaks after the shingles.

The tops of inclined rafters are fastened to the ridge. To shed water away from the eave most roofers add a metal drip edge right to the roof deck covering it with the membrane. Roof sheathing 2nd layer of plywood.