If not replace bad wood with new plywood sheathing or 1 x 6 sheathing boards whichever is applicable to your type of roof.
Replacing roof boards plywood.
Clamp a 1 by backing board in place and screw the new rafter to it.
Protect the edges of the plywood soffit from water penetration with a waxy sealer such as anchorseal.
Rotted plywood can cause a number of issues.
Cdx plywood is a construction grade type of plywood that is designed for exposure to the elements.
Today a shiplap roof is usually 60 years old.
The tear off gets a lot more complicated if you have something other than asphalt up there.
Moisture causes wood to rot and rotten wood absorbs water even more readily than fresh wood.
As roofing contractors in seattle we are often asked why do we need plywood over our old solid sheathing.
Now it s time to replace the roof plywood and any other damaged wood in the roof area.
Screw the rafter to the chimney cleat as well.
If you were able to keep the removed section in one piece measure it.
Open spaces form between the once tightly fitted shiplap boards.
This particular type of plywood is crafted from layers of wood stacked on top of one another with alternating grain patterns in each layer.
The keyword here is solid it used to be standard to use shiplap 1 boards tongue groove or other boards for the roof deck.
Make minor repairs on the roof if it is in good condition.
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.
If not climb the roof and measure the opening so you can cut the replacement piece to be a perfect fit.
After the 1960s the predominant residential roofing substrate became 1 2 cdx plywood.
Over time shiplap fir wood resin dissipates causing the boards to shrink crack form knot holes and become extremely brittle.
Most construction sites will consider the use of either osb or plywood for the roof.
If you can see original wood shingles on the underside of your roof when you re up in the attic you ll need not only to tear everything off but also to install new plywood decking all of which likely adds 5 000 or more to your costs.
Select plywood or oriented strand board that is the same thickness as the wood you are replacing.
It can withstand moisture for a brief period of time but may become warped and delaminated with consistent exposure to the elements.