A new construction wall in a cold climate
I am building a new addition in southern Ontario and would like to use 1″ to 1.5″ natural stone veneer for the exterior. Stone veneer would be applied over metal lath screwed into studding.
I would also like to use 1″ to 2″ of rigid foam insulation as exterior sheathing over 2×6 wood stud walls without an interior vapour barrier.
I was hoping to get some help detailing the wall.
Can the metal lath be applied directly over the rigid insulation and screwed in the studs without any wood sheathing anywhere?
Does there need to be wood sheathing over the rigid insulation and under the metal lath?
Does there need to be wood sheathing over the studs but not under the metal lath?
From what I have been reading on GBA some rigid insulation can be a water barrier but is it ok to double up and apply another water barrier like house wrap in the wall make up .
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Replies
Wayne,
1. You can install foam sheathing with or without plywood or OSB under the foam. If you choose to install the foam sheathing without any plywood or OSB, you need to come up with a plan to provide bracing (let-in braces, metal T-braces, or plywood at the corners).
2. It's very risky to install stone veneer over a wood-framed wall unless you include a ventilated rainscreen gap between the back of the stone veneer and the sheathing.
3. If you’re installing stone veneer over foam, here’s how to create a ventilated rainscreen gap:
- Install 1x3 or 1x4 vertical strapping on top of the foam, screwed through the foam into the studs.
- Fasten paper-backed metal lath to the strapping, and proceed with a standard installation of stone veneer.
Thank-you Martin