2 Layers Of Roof Rafters

See rafter run to outer wall calculator below.

2 layers of roof rafters. Epdm roof membrane 90 mil fully adhered membrane only 0 56 lbs. The ridge cut also called the plumb cut at the top of the rafter the birdsmouth cut which itself comprises 2 different cuts where the rafter meets the building s wall and the tail cut at the base of the rafter. This synthetic layer which replaces felt paper covers the entire roof deck and is the second line of defense against leaks after the shingles. When you cut the rafters you ll need to make 3 separate cuts.

Ice and water shield self adhering. Rafters rafters make up the main framework of all roofs. When framing a roof figure 7 2 carpenters must be familiar with commonly used roofing terms figures 7 3 and 7 4. Allow for ridge thickness when determining rafter run to outer wall.

Gypsum roof board 1 2 inch thick. The tops of inclined rafters are fastened to the ridge. Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through. For rafters spaced 20 or more inches apart 1 2 or 5 8 inch plywood is recommended.

My house has 1 2 cdx over 7 8 fir skip sheathing. It is very easy to cut completely thru a 2x12 rafter and not know it. Roof sheathing 2nd layer of plywood. Don t be afraid to pay up to 100 for a well documented report with photos showing what they found.

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. They vary in size depending on length and spacing. Half building width minus 1 2 ridge thickness. The most common rafter spacing is 24 inches and 5 8 inch plywood is recommended for that.

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. This is especially true if you ve overlayed your new shingles on top of warped shingles. To shed water away from the eave most roofers add a metal drip edge right to the roof deck covering it with the membrane.