Strapping necessary under metal roof?
I’m building a 7:12 pitch gable roof in Nova Scotia, Canada. Planning on either 1/2″ or 5/8″ CDX sheathing over the trusses and will cover with Mento 3000 as our underlayment. The metal roofing we’re using (see attached) is not standing seam, but does have ridges that (maybe?) would allow some drying between the metal and the the underlayment. Given this assembly, how necessary do you think it is to add horizontal (or diagonal) 1X strapping between the metal and the underlayment? Should I think of this drainage plain like a wall rainscreen, or is it different in kind?
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