Help- granite rock exterior
Hi
Zone 6-6a
Front of house on main level has real stone.
I’m in the process of removing the drywall (entire house), air sealing and then replacing drywall using air tight method.
How do I tackle the wall cavity behind the stone.
Would this work:
1. Spray foam all crevices and framing to sheathing (1/2″ fiberboard)
2. Install house wrap nice and neat and well sealed inside the cavity
3. Reinstall the R10 Kraft faced insulation
4. !!!! Do I install 6 mil vapor barrier?????
5. Install air tight drywall.
Is there a better option.
Last year or so I asked here about 6 mil and the consensus was that I didn’t need it. So 3 out of the 5 rooms on the second level are complete (interior only)
Not being able to house wrap and add 3″ of insulation behind the stone has me a bit stumped 🤔
I plan on removing the wood siding, installing a WRB, rain screen and exterior insulation ( 3″ reclaimed EPS or ” roofmate”)
It seems the roofmate is plentiful. Is roofmate a good option.
Thanks again everyone!!
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Replies
Masonry veneer of all types needs a gap behind it or you will have long-term moisture problems.
Poly is never a good choice for CZ6 walls and even worse when there is a "reservoir cladding"--one that can hold moisture, such as masonry. When sun hits the damp masonry it will push the moisture into the wall, regardless of the season. Eliminating an interior vapor retarder can work in CZ6 when the moisture can pass easily to the exterior, which it won't be able to do with stone veneer. The safest approach is to use a variable permeance membrane--one that blocks air and greatly reduces vapor movement, but opens up for drying if moisture in the cavity is elevated.
Thanks Michael
About 2 years ago I replaced the windows in this wall. I can confirm it has an air gap behind the stone.
The Wall in question is approx 14x8 with a RO of 10x6. So basically a normal stud cavity on both sides and under, the top is all header.
I can't justify the cost for smart barrier for such a small area.
Can you recommend a different approach.
Also.. I've opened the wall and all looks good in there.
Stone- air gap -1/2" fiber board- 2x4 R10 Kraft faced - 4 mil poly- drywall.
Thank you