Replacing Roof Boards Plywood

Make minor repairs on the roof if it is in good condition.

Replacing roof boards plywood.

These 8 to 12 inch wide boards were nailed together tight. Moisture causes wood to rot and rotten wood absorbs water even more readily than fresh wood. It can withstand moisture for a brief period of time but may become warped and delaminated with consistent exposure to the elements. Protect the edges of the plywood soffit from water penetration with a waxy sealer such as anchorseal.

If not replace bad wood with new plywood sheathing or 1 x 6 sheathing boards whichever is applicable to your type of roof. After the 1960s the predominant residential roofing substrate became 1 2 cdx plywood. If you were able to keep the removed section in one piece measure it. As roofing contractors in seattle we are often asked why do we need plywood over our old solid sheathing.

This is really just a rough draft of the post a collection of photos with captions. Rotted plywood can cause a number of issues. Over time shiplap fir wood resin dissipates causing the boards to shrink crack form knot holes and become extremely brittle. I ll be on the road for a few months and won t have time to complete these posts until after but for those of you who ve written wanting to see the rest of the project hopefully this is better than nothing.

The keyword here is solid it used to be standard to use shiplap 1 boards tongue groove or other boards for the roof deck. Clamp a 1 by backing board in place and screw the new rafter to it. Select plywood or oriented strand board that is the same thickness as the wood you are replacing. Rotted plywood cannot support the weight of a roof the way healthy wood can nor can it safely grip the nails put into the roof and keep them held firm.

Open spaces form between the once tightly fitted shiplap boards. Cdx plywood is a construction grade type of plywood that is designed for exposure to the elements. If not climb the roof and measure the opening so you can cut the replacement piece to be a perfect fit. This particular type of plywood is crafted from layers of wood stacked on top of one another with alternating grain patterns in each layer.

Today a shiplap roof is usually 60 years old. Most construction sites will consider the use of either osb or plywood for the roof. The tear off gets a lot more complicated if you have something other than asphalt up there.