Are furring strips needed for Galvalume siding?
I am about to install metal siding on small guest house and not sure I need to have furring strips. Most of the information I’m finding discusses metal roofing installation, or vinyl siding.
As the structure sits now, all exterior walls are framed with 2”x6” lumber 24” OC, OSB sheathing with taped seams, 1” polyiso foam sheathing, and Tyvek house wrap. Interior wall space will be insulated with mineral wool insulation.
I’m curious if I need to use furring strips – I have 26ga metal siding I’d like to install directly on top of the house wrap/foam with 2” screws through to the studs. This would provide better support and ‘purchase’ for the metal siding, but wasn’t sure if I needed to consider a larger air gap for drainage?
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Replies
Andrew,
The answer depends on at least two factors:
1. Whether the siding has a flat profile or a corrugated profile; and
2. The installation instructions of the siding manufacturer.
Thanks Martin, good points. The metal panels are used and being repurposed for this structure, so I don't have instructions from the manufacturer. It looks to be a fairly standard 36" classic ribbed panel with ribs spaced approx. 3" apart, with every 3rd rib being higher than the others. It's not a full corrugated panel.
Andrew,
If I were you, I would install the metal panels on horizontal furring strips, 24 inches on center. That way, there will be a much lower chance that moisture will be trapped on the back side of the panels, leading to rust.