Interior foam, veneer stone, etc.
Wow, my second (plus) question! I have lurked for a long time, finding most of my questions answered by searching, but I have been having a hard time finding solid answers as my project plans get more specific.
Current home: zone 5 (Southern NH). House built circa 1970, with the associated quirks and so-so insulation level. Slab foundation with poured walls. Walkout basement with three walls about two thirds below grade. The fourth wall (I will call it the “front”) is a “half wall” with the remaining upper half being stud construction. The whole front is exposed, being where the entry door and garage door is.
The upper half of the front is covered with cedar shingles with the concrete portion exposed. By the way, there isn’t even any felt under the shingles right now, but the sheathing is doing fine (had to replace some broken shingles so I could see what’s going on). The rest of the house is aluminum siding which covers down to and including the rim joist area.
Current plan: 3 inches of rigid against the interior of the concrete wall (all sides). 2 inch eps or xps with a “cover” of 1 inch Thermax (for fire rating) on the rim joist (cut and cobble).
Near future plans: Currently, in the stud portion of the front wall (2×4), it’s FG with poly barrier. I want to replace the FG with Roxul (R15) and 1″ rigid (most likely xps), for additional R and to provide a thermal break. No other VB/VR other than the rigid.
Further future plans: Replace aluminum siding with vinyl siding (finish is so old, it’s “powdering”), with veneer stone. The veneer stone will only be on the front of the house (most likely), covering what is now exposed concrete going up the upper half wall and stopping where the current aluminum siding (to be replaced by vinyl) is.
Question 1: Just want to make sure that the near future plan of roxul between studs and xps over that (with furring and drywall) will be OK (exterior will remain shingles).
Question 2: With Further future plans of veneer stone to cover that area, will the required two layers of felt, lathing, scratch coat, then veneer stone present a problem with the Roxul/xps on the interior. I am thinking it will still allow drying to the outside?
Question 3: Since the siding will be pulled off to replace, is it plausible to then put rigid foam against the sheathing (plywood) before the siding? My concern is that there is likely poly vb in the main floor walls (as was the practice), so putting foam on the exterior of the sheathing may result in a moisture “trap” between the vb and the foam?
Question 4: If Q3 is plausible, would I have to somehow “butt” the foam/siding out somewhat or leave some kind of gap at the rim joist area to take into consideration that there’s the rigid on the inside (to allow for exterior drying)?
Thanks to all the geniuses on this site!
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