Ensure that the plywood deck is strong enough to withstand the added weight of the metal panels.
Do you need plywood under metal siding.
Do you need plywood under metal roofing.
No the purposes of the plywood roof decking are to give lateral stability to the rafters trusses and create a walking surface.
Metal roofing should serve both these purposes i m.
In a barn shop or other outbuilding you can attach your metal roof directly to the purlins.
Metal roofing requires a solid substrate.
It depends if you need the shed heated for any thing if not no you do not need a plywood layer.
For many applications a layer of plywood underneath your metal roofing is an unnecessary expense.
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.
Considering when to.