Roof Sheathing Over Old

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.

Roof sheathing over old.

Today a shiplap roof is usually 60 years old. There does not appear to be any roof leaks but from poking at the sheathing from below there appears to be dry rot. Over time shiplap fir wood resin dissipates causing the boards to shrink crack form knot holes and become extremely brittle. But can he simply install new plywood over the old.

Because the plywood roof sheathing under the shingles has become brittle and weak he plans to install new plywood as well as new shingles. Roof sheathing provides an area where the surface material can be attached but it also helps keep the trusses and or rafters properly spaced. The anchor of the system that keeps. It is in your best interest to apply solid sheathing over the existing shiplap for your roofing system to securely fasten to.

Sheathing is installed over multiple trusses rafters so it essentially turns them into one cohesive unit instead of individual structural members. Housing and urban development hud rehab guide. Sheathing works with other components of the roof as well. Question 1 which is preferable from a quality perspective cost is secondary.

Two questions about replacement of roof sheathing. Attic ventilation comprises of a poorly installed ridge vent with no soffit vents. The roof is sheathed with either 3 8 or 7 16 inch plywood. The keyword here is solid it used to be standard to use shiplap 1 boards tongue groove or other boards for the roof deck.

50 year old house with 3 8 plywood sheathing on trusses spaced at 24. As roofing contractors in seattle we are often asked why do we need plywood over our old solid sheathing. I have it under contract to resheath and reroof. It is now warped and wavy.

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. Roof shingles are to be replaced.