Insulating crawl space in a house on piers
I have a house on piers. Height above natural ground varies from 1 foot to 4 feet. “Floor” is boulders and sand. House is skirted with vinyl siding with considerable gaps.
Climate is cool–I’m just at the 45th parallel in Bracebridge, Ontario Canada and am on the water. There are no issues with flooding at the house. I will be adding to the house in the spring as well as rewiring and changing plumbing, but need help on insulating the existing house now. I would prefer not to have to dismantle stuff I put in now when I add on. Conversely, is it better to wait and do it all when the addition goes on. I should add that I will be doing a lot of the insulation myself.
The space has a “warm room” (pretty well insulated and with a baseboard heater) that houses the water line under the house (it’s buried until the crawl space), the pressure tank, the HWH, Iron and Tannin tanks, UB light and 2 filters. Septic piping is also here and exits well below ground.
Rockwool is between the joists, but joist ends are exposed.
I have no idea at present what (if any) subfloor insulation is present, but the exposed joist cavities in the warm room indicate that the subfloor is plywood. I do have room to add rigid foam above it before I lay new floor. I could use foil backed foam (foil side to the interior) if it will net a benefit, but don’t know about vapour issues.
Crawl space is damp in the summer. I bought in May, so have no experience with winter conditions.
I had planned to insulate under the joists with Rockwool Comfortboard, then apply some sort of vapour barrier. My neighbour, a contractor has suggested that I frame in the wall space between the piers and use closed cell spray foam to seal down to the boulders.
My gut says to isolate the living space.
I know that I will need a barrier of some sort on the ground, but poly seems to be too fragile if I’m using the space for outdoor furniture/kayak storage.
What say you all?
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