Do You Need Plywood Under Metal Siding

Considering when to.

Do you need plywood under metal siding.

It adds insulation waterproofing and structural support for the framing. For many applications a layer of plywood underneath your metal roofing is an unnecessary expense. 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.

Ensure that the plywood deck is strong enough to withstand the added weight of the metal panels. Do you need plywood under metal roofing. Metal roofing should serve both these purposes i m. 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.

In a barn shop or other outbuilding you can attach your metal roof directly to the purlins.