I’ve been wracking my brain on this one. I’ll be building in zone 6 and want to incorporate 3 inches of exterior mineral wool insulation with a cultured stone cladding. It seems that these two things don’t like to play well together and I can’t figure out how to make this work.
I was thinking I could use Cascadia clips or Knight wall clips with Z girts and cavity rock insulation in between. Then attach a metal lathe to the girts and apply the thin stone veneer on top of that. However I’m not sure if I’ll need more support for the lathe as it will be floating in between the Z girts every 24 inches. Would it make more sense to use cement backer board or quarter inch plywood to create a more stable surface for the lathe before the stone veneer goes on? If I used plywood would it need any water protection?
Are there any better ways to do this? Mineral wool seems to be the best exterior insulation up north to let the walls dry to the exterior but even the comfort board isn’t quite stiff enough for mid weight cladding. Could I just forgo the clips and use comfortboard with strapping?
Replies
You can support lumpy stucco off mineral wool directly over strapping:
https://www.rockwool.com/siteassets/o2-rockwool/documentation/technical-guides/commercial/rockwool-cladding-attachment-and-support-details_en.pdf
Not a huge fan of that though, anything stucco is too easy to install it incorrectly, for the cost and complexity go with regular stone veneer.