Do You Need Plywood Under Metal Siding

Rotted sagging areas in your roof s plywood decking should be replaced prior to installing metal panels in order to prevent costly repairs in the future.

Do you need plywood under metal siding.

Metal roofing should serve both these purposes i m. Do you need plywood under metal roofing. 1 you said some metal roofing should never have firring strips i have certainly seen that with some of the very thin steel or weak aluminum decking which could never stand even a foot of free span over firring strips without crumpling buckling under someone walking on it so they would have to lie flat on the water barrier over the sheathing. Metal roofing requires a solid substrate.

It adds insulation waterproofing and structural support for the framing. In a barn shop or other outbuilding you can attach your metal roof directly to the purlins. Considering when to. No the purposes of the plywood roof decking are to give lateral stability to the rafters trusses and create a walking surface.

It depends if you need the shed heated for any thing if not no you do not need a plywood layer.