concrete block wall retrofit
Hello all and thanks in advance for your help.
I’ve been reading articles here and on the buildingscience.com website but was hoping that someone could weigh in on our particular situation.
We’ve recently demoed a lot of stone — a chimney and facings on exterior and interior walls — from our house in Asheville NC — climate zone 4A. The house was constructed, not very well, in a couple of phases, by our DIY predecessors, and has concrete block walls.
The complications that adding exterior insulation would bring are not worth the benefits to us, and this is just one leaky wall out of many. What we have now is concrete block up to regular ceiling height and then a framed wall on top of that to make a half-cathedral ceiling.
Our current plan, on the inside, is to glue/fasten 1″ rigid foam insulation to the block wall, and then add a 2×4 framed wall with batt insulation, and finally sheetrock. Questions: What kind of rigid foam insulation would be best? Should we paint a “fluid-applied, vapor-permeable air and water barrier” on the inside of the concrete block wall? There’s already some yellow coating on it… Is it ok for the stud wall to press up against the rigid insulation or should there be a gap? Is it ok if the rigid insulation stops at the top of the concrete block wall?
On the outside, we were going to add the “fluid-applied, vapor-permeable air and water barrier”, then building paper, and then stucco installed on a drainage mat.
Thanks again for your thoughts and advice.
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