Most roof decking is made from sheets of plywood.
2 layers of roof sheathing.
I m not a fan of spray foam.
Can you double up plywood roof sheathing without inviting disaster 2000 sf of 1 2 cdx ply went on the roof before i had a chance to take a look at it and it is really sorry stuff.
Skinning over old sheathing does occur but i have never seen someone skin over plywood in that condition.
Roof sheathing materials plywood.
If you re in search of quotes for a roof sheathing job improvenet can put you in touch with up to four local contractors for free.
Assuming your roofing contractor is using standard 36 wide 15 roofing felt double coverage means that each layer of felt put down across the roof laps 19 over the upper half of the previous course.
So anywhere along the gable end that you can see the felt you ll see two layers.
Plywood used for roof decking is typically called sheathing and carries a grade stamp indicating its load and span ratings and other performance factors.
The first course starts with an extra 1 2 wide run.
Wood shakes minimum 3 4 sheathing wood shakes nail type minimum length.
Poor ventilation from a past roof along with 3 ply equals that delamination.
Based on the pictures alone i don t know what to say.
I think there are better ways to design an unvented roof for example by using rigid foam above the roof sheathing instead of closed cell spray foam on the underside of the roof sheathing.
Plywood is layers of wood.
It s usually a peel and stick product that adheres directly to the roof deck.
Comes in standard 4 by 8 foot sheets is strong.
I am replacing a roof right now built in 1982 and the 3 ply is delaminated pretty heavily.
It got nailed over 2 x 12 joists 24 o c.
Most building codes allow for two layers of asphalt shingles on a house so stripping off everything down to the plywood sheathing may not be your only choice.
On a 2 12 pitch roof.
It s up to you.
Should you sandwich roof sheathing between two impermeable layers.
Roof deck is the roofing material that sits on top of the roof trusses.
Dimensional comp shingles over 3 tab 1 1 4 1 1 2 1 1 2 1 1 2 more than 1 layer of roofing not recommended over 3 8 sheathing.