Roof Sheathing Over Old

The roof is sheathed with either 3 8 or 7 16 inch plywood.

Roof sheathing over old.

Roof shingles are to be replaced. The contractor has asked if it is possible to leave the old sheathing in place and install the new 5 8 inch sheathing over the top of it. Sheathing works with other components of the roof as well. But can he simply install new plywood over the old.

Roof sheathing the material nailed to your trusses or rafters to which your roofing is attached is your roof s workhorse. Because the plywood roof sheathing under the shingles has become brittle and weak he plans to install new plywood as well as new shingles. As roofing contractors in seattle we are often asked why do we need plywood over our old solid sheathing. It is in your best interest to apply solid sheathing over the existing shiplap for your roofing system to securely fasten to.

The keyword here is solid it used to be standard to use shiplap 1 boards tongue groove or other boards for the roof deck. It is now warped and wavy. 50 year old house with 3 8 plywood sheathing on trusses spaced at 24. Housing and urban development hud rehab guide.

The anchor of the system that keeps. Walking on the roof feels very spongy. I have it under contract to resheath and reroof. Two questions about replacement of roof sheathing.

Roof sheathing provides an area where the surface material can be attached but it also helps keep the trusses and or rafters properly spaced. This guide was developed and edited for old homes from original material in the u s. There does not appear to be any roof leaks but from poking at the sheathing from below there appears to be dry rot. Question 1 which is preferable from a quality perspective cost is secondary.

Apply new roof sheathing osb directly over old sheathing sagging inch plywood or rip the old sheathing off and apply new sheathing to the trusses. Today a shiplap roof is usually 60 years old.