Old Roof Sheathing

Open spaces form between the once tightly fitted shiplap boards.

Old roof sheathing.

The keyword here is solid it used to be standard to use shiplap 1 boards tongue groove or other boards for the roof deck. Shingles stain condensation collects and high winds carry roofs wherever they please. These 8 to 12 inch wide boards were nailed together tight. Never attach roof sheathing with staples.

After the 1960s the predominant residential roofing substrate became 1 2 cdx plywood. The typical thickness range for sheathing is 3 8 to 3 4 inch. 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 comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame.

But you must take care to install shingles correctly so they lie flat. As long as the new plywood itself can span the distance and carry the roof wind seismic and snow loads for your region adding new ply over old is just fine. The anchor of the system that keeps water out the base onto which you nail your roofing the major part of the brace system for your trusses rafters a key piece of the stiffening system that protects your house from earthquakes and blasts of wind. But can he simply install new plywood over the old.

Over time shiplap fir wood resin dissipates causing the boards to shrink crack form knot holes and become extremely brittle. Roof sheathing materials plywood. Comes in standard 4 by 8 foot sheets is strong. 8d ring shank nails should be used instead.

If conditions are right new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing. Sheathing should be a minimum of 19 32 inch thick. Putting a safe roof over your head isn t necessarily a one time deal. The new plywood thickness should be.

And if you re still wondering what roof sheathing is and what materials are typically used read on and satisfy your curiosity. Today a shiplap roof is usually 60 years old. As roofing contractors in seattle we are often asked why do we need plywood over our old solid sheathing.