WRB decision for cold weather situation
I’m doing a full gut/rehab on a 1950’s cape cod 1.5 story house in Nova Scotia, Canada this winter. I want to run my plan by you all to make sure i’m not wasting materials or choosing the incorrect ones.
I’m in zone 6 and will have an HRV for ventilation.
The house will be stripped down to the rough 1x sheathing, repaired where needed and covered with OSB.
Now for the WRB i’m considering doing Henry’s VP100 with their Hi-Tac primer due to the freezing temperatures (-5C to -15C) but i’m not sure if its needed or would be overkill since i’m putting 2 layers of foam on top. The alternative is Tyvek.
Window flashing will be Henry’s Air-Bloc LF liquid flashing encompassing the entire window bucks. The bucks will be 2 2×4’s with 3/4 XPS foam sandwiched in between.
Next comes 2 layers of 1.5″ GPS (Graphite EPS) with taped seams and 1×3 for the rain screen. Siding will be vinyl.
Windows are Triple pane casement
Walls are rough 1×4’s and will be insulated with fiberglass batts or open cell foam. (Figured fiberglass would work considering air-tight envelope)
No vapor barrier but if the building inspector forces the issue i’ll use Majrex or similar.
Basement walls will be closed cell foam at 2″ thick with 2×4 framed walls filled with fiberglass, headers will be 3″ foam with fiberglass.
Cathedral ceiling will be 7″ closed cell foam from top of the walls to the peak.
Please note that Zip sheathing is not available anywhere near me or i’d use that.
Fiberglass was chosen to keep costs down but may upgrade to open cell foam.
Heating system will be 2 x 12000 btu mini splits.
Water heater will be Rheem or similar heat pump. Sanden is out of budget
GBA Detail Library
A collection of one thousand construction details organized by climate and house part