No Sheathing Under Roof

Sheathing is installed perpendicular to roof trusses.

No sheathing under roof.

Never attach roof sheathing with staples. 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. 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. 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.

Sheathing should be a minimum of 19 32 inch thick. Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. How to prevent condensation under a metal roof. When open cell spray foam is used a low perm class ii vapor retarder is installed where required.

Modern metal roofs are expected to last 30 years or longer. 8d ring shank nails should be used instead. Owners of agricultural buildings man caves and horse barns all are worried about the corrosive effects of condensation. If you re wondering how to prevent condensation under a metal roof you re not alone.

It is nailed directly to the rafters. A leak free roof membrane that is fully adhered to the roof sheathing should be installed. 3 benefits of rigid foam sheathing. Here s how to fight back against the enemy within.

Currently there is no sheathing or tar paper under the metal.