While metal roofing doesn t require plywood underlayment there are circumstances in which you may wish to install plywood to anticipate future roofing needs or to offer additional soundproofing.
No sheathing under roof.
Underneath it is the attic space followed by a suspended ceiling.
Here s how to fight back against the enemy within.
If you re wondering how to prevent condensation under a metal roof you re not alone.
Sheathing should be a minimum of 19 32 inch thick.
Sheathing is installed perpendicular to roof trusses.
8d ring shank nails should be used instead.
Never attach roof sheathing with staples.
It is nailed directly to the rafters.
When open cell spray foam is used a low perm class ii vapor retarder is installed where required.
How to prevent condensation under a metal roof.
July 28 2017.
Owners of agricultural buildings man caves and horse barns all are worried about the corrosive effects of condensation.
The current state and local building codes for the minimum r value of air impermeable insulation required for the roof assemblies in the home s climate.
More effective insulation with r values ranging from 3 6 to 8 0 rigid foam sheathing has much better insulation per inch than other materials i e.
A leak free roof membrane that is fully adhered to the roof sheathing should be installed.
Plywood has an r value of 1 25 and fiberglass batts have an r value of 3 14.
Currently there is no sheathing or tar paper under the metal.