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.

For many years it was acceptable to put even the third layer. A roof is one of the most vital components of a house. 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.

This synthetic layer which replaces felt paper covers the entire roof deck and is the second line of defense against leaks after the shingles. Rafters rafters make up the main framework of all roofs. They vary in size depending on length and spacing. Pros and cons of adding a second layer of shingles.

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. If you have done some serious research on roofing then you have probably heard about adding a second layer of shingles on top of the old ones. A 2 12 roof slope means your roof has 2 inches of vertical drop for every 12 inches of horizontal distance. For rafters spaced 20 or more inches apart 1 2 or 5 8 inch plywood is recommended.

If the old roof has slate clay cement asbestos tile or wood shakes the installer must remove the material. They are inclined members spaced from 16 to 48 inches apart. The most common rafter spacing is 24 inches and 5 8 inch plywood is recommended for that. Asphalt shingles typically can have one more layer added over the top two roofs total.

On most flat roofs such as epdm tpo or modified it is perfectly acceptable to two layers of roofing. Don t be afraid to pay up to 100 for a well documented report with photos showing what they found. Posted july 31 2018 by onpage marie. If the existing roof foundation is inadequate for the new roof or has two or more layers the rules prohibit the installation of a new roofing system.

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. Steep sloped roof products such as tile slate metal and shakes only allow one layer. Replacing a roof can be very expensive and exhausting at the same time.