Stucco over brick
cathg
| Posted in General Questions on
A friend of mine is doing a new build in Oklahoma, climate zone 3A. Their builder is planning on doing zip sheathing, with brick cladding and then stucco directly over the brick and r-13 spray foam interior(open cell). There will be a small air gap between the brick and the zip, but is this assembly just asking for moisture issues?
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Replies
Catherine,
Do you know what thinking behind using brick as a substrate for the stucco is? On the face of it it makes no sense.
I agree. Builder said because in their climate they get hail so if they use perma base or something soft, the hail can crack the stucco
Catherine,
I don't know enough about building in warm climates to give any useful advice, but it would seem to make more sense to either commit to building out of masonry, or wood frame. The combination being proposed seems like the worse of both worlds.
I'm with Malcom, maybe this is a regional thing. Stucco over cement board is pretty sturdy but you might have some super hail we don't get here.
In either case, you are looking at a reservoir cladding. This means you need an vented air gap between the cladding and zip. Code is usually 1" and venting and drainage on the bottom is a must. Make sure the gap is kept somewhat free from mortar droppings.
Since you are already doing zip which will need to be taped at the seams, you will have a pretty solid air barrier. The spray foam between the studs doesn't buy you anything except extra cost and the inherent risk of a spray foam install. I would stick to regular batts, if you want better, go for high density ones (either fiberglass or mineral wool, both work just as well).
Thanks Akos!