Framing New Roof Over Existing Roof

The roof is erected over a deck that will be screened as an outdoor living area.

Framing new roof over existing roof.

Box beam gable framing new gable overhang is framed in the form of a box beam hanging off of a new layer of roof plywood roof sheathing cantilevered over the top of the 3 layers of rigid insulation. Finish the new roof by nailing on osb sheathing covering it with roofing paper and nailing in metal flashing along the valleys and metal drip edge at the eaves. Fold new shingles over the new valley onto the old roof overlapping by at least a foot. Roofs are framed out of lumber and pieced together in a series of triangles designed to bear the load.

This new roof with a higher pitch can be accomplished with premade roof trusses and typical asphalt shingles. Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option a properly installed layover roof can look and function as well. Sounds simple enough right. There are a few situations where roofing over an existing roof just isn t possible.

Unfortunately it s not an option for everyone. If you are building a new home putting an addition on an existing home or replacing your roof down to the rafters you will need a new roof frame. The old shingles are visible inside the framing of the new roof. We aren t planning on going up a floor so the roof would only be marginally higher than it is now.

The roof sheathing on the old roof is not rotten just not up to the standards my dh thinks it should be. Then nail shingles on the new roof and exposed areas of the old roof. We are planning to frame the new roof over the existing roof. When you recover your old roof stays and the new roof gets installed on top.

Metal roofing materials are available in several styles that require different fastening applications but are most commonly screwed to the roof framing or sheathing material. Shown is the new rafter system of the porch. The exposed edges of the 3 layers of rigid insulation are no longer exposed. Dh is a very skilled carpenter and is confident that he can do this work.

The new ridge will tie into the existing roof as a hip and valley offshoot. Roofing over your existing roof is not always possible.