Insulating House in Zone 6A
Hi there, we are currently renovating a 1954 sidesplit in Toronto Canada (Believe this is Zone 6A). On the main floor, there is a 6″ slab which doesn’t have any insulation or poly below. Likewise, the basement is similar, but only has a 3″ slab. We have had to cut channels in the existing concrete slab and will need to pour the new floor for the addition.
We are now looking to insulate both floors. The plans has been to use the following:
Concrete > Poly Vapour Barrier > 2″ EPS (Amvic Silverboard) > 3/4″ plywood T&G tap-conned > 3/4″ Hardwood or tile. In the basement, we would sub the hardwood for laminate.
In the basement, our walls will be 10″ Block Foundation > 2″ EPS Silverboard > 2×4 with R14 Roxul > Drywall sitting on top of the subfloor.
Some questions:
1) Do I need to worry about bathrooms flooding etc. and have some type of airgap below the foam (esp in basement)? Maybe a delta product?
2) Any concerns with putting the subfloor over recently poured concrete? I can’t leave it to dry for months, but a week or so may be possible.
3) Do I need to be buying the blue/pink insulation, or will silverboard work? I notice it has the little white balls.
4) Anything else I should be concerned about?
Thanks in advance for all your help – I have learned so much on this site.
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Replies
James,
Q. "Do I need to worry about bathrooms flooding etc. and have some type of airgap below the foam (especially in basement)? Maybe a Delta product?"
A. Any time that you decide to finish a basement, you are assuming risk. Basement spaces are at risk of flooding. If you don't want to accept that risk, don't use your basement as finished space.
You can never eliminate the chance of flooding. An air gap below the foam won't help you in a flood event.
Q. "Any concerns with putting the subfloor over recently poured concrete? I can't leave it to dry for months, but a week or so may be possible."
A. If you install a layer of polyethylene, followed by a layer of EPS, I wouldn't worry.
Q. "Do I need to be buying the blue/pink insulation, or will silverboard work? I notice it has the little white balls."
A. EPS will work fine for this application, but I'm not familiar with Amvic Silverboard. If you have any doubts, call up the manufacturer.
-- Martin Holladay