Rain Screen: Horizontal furring strips with corrugated metal siding installed vertically
I am installing corrugated metal siding vertically over 1″ Roxul Comfort Board exterior insulation, thereby necessitating a horizontal furring strip that can bear the weight of the siding. We originally furred the windows out by 2 3/4″ with the idea that we would use 1 x something vertical furring strips to allow drainage, then 1 x something horizontal furring strips for the metal. I believe it is a good system, but am now preferring to double my planned exterior insulation to 2 inches and reduce the amt of furring if possible while working within the parameters of the 2 3/4″ window pop-outs.
Specifically, I am wondering if the vertical channels in the corrugated metal might be sufficient for drainage if I add the extra 1″ roxul in lieu of the vertical furring? I would also consider bevelling the horizontal furring strips toward the exterior to move any bulk water toward the backside of the metal channels. Does this sound like a system that would would work? Any input greatly appreciated.
Other information: 1/2 plywood sheathing, typar warp, planning a bug screen at base of rainscreen, climate is quite wet – interior BC
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