Plywood Over Shiplap Roof

But since the rafters will be open this plywood will be visible from the patio.

Plywood over shiplap roof.

If it is a hot roof and the design assumes airtight sheathing it would be easy at this point to install plywood zip sheathing and tape it. Shiplap does work but requires good intake exhaust. These 8 to 12 inch wide boards were nailed together tight. Shiplap roof decking was widely used in the 50 through 80 s era when plywood hadn t yet made its way into new construction.

Sometimes on older houses they have had so many different roofs that the deck is all shot up splintering in this case a redeck is in order. In most cases if it is a cold roof shiplap will be fine. Over time shiplap fir wood resin dissipates causing the boards to shrink crack form knot holes and become extremely brittle. I was low balling it to see if indeed as the roofer said low slopes necessitate adding plywood over shiplap.

Thanks for the heads up. The keyword here is solid it used to be standard to use shiplap 1 boards tongue groove or other boards for the roof deck. If you have roofers that don t know the difference between shiplap skip sheathing find a roofer that does. As for slope i haven t actually measured it.

As roofing contractors in seattle we are often asked why do we need plywood over our old solid sheathing. I am sure i am not the only one that has been deceived by what looked like venting but wasn t. Shiplap doesn t have any gaps in the boards and can be roofed over as is usually. Today a shiplap roof is usually 60 years old.

Open spaces form between the once tightly fitted shiplap boards. At one point in time it was standard to use shiplap tongue and groove one inch boards or other boards for your roofing deck. Whenever your roof was first installed the nails were put into the solid wood. The shiplap does look like its in good condition however i haven t put nails into it or given it any other test of strength.

After the 1960s the predominant residential roofing substrate became 1 2 cdx plywood. Shiplap is now considered an enemy of asphalt shingles. These wider boards were all nailed tightly together. However that isn t the case.

There is another issue whether the shiplap is aiding your household air infiltration. Remember the keyword is solid. I m building a solid patio roof and was planning on using 1 2 plywood over the rafters 24 oc for the roof with spruce shiplap over the eaves to match existing house look.