Good morning all. I have a question about sub floors on a concrete floor. I live in northern Canada where winter temps get down to -45c on occasion, with the odd winter day that gets above the freezing mark. I have started to turn a attached garage into living space and the concrete floor is a bit uneven. We excavated around three sides and insulated with foam, after having the concrete jacked up to almost even. I would like to install a subfloor so we can put down hardwood flooring. Headroom is not an issue, 9′ ceiling. I am looking for suggestions on the proper installation technique so we don’t end up with moisture problems under the new floor. I would like to add that we are doing all of the work ourselves, if that makes a differance. Thanks for any help on this one.
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Since you have the headroom, you should think about adding a floor system that includes substantial insulation.
Lay a vapor barrier on the concrete, overlapping any seams. Then build the floor framing -- 2X6's maybe. Fill those cavities with the best insulation that you can afford.
Then lay the plywood subfloor on that framing, and hardwood on that.
Unless you're the lead dog, the view just never changes.
Do you think I should try sealing the concrete before laying down a vapour barrier?My concern is if the vapour barrier should be breached at some point, would we be looking at problems with moisture migrating through the concrete? As far as insulation goes, any suggestions?Have fun! Nobody gets out alive.
My concern is if the vapour barrier should be breached at some point, would we be looking at problems
Sealing the concrete might help a little.
As for insulation, the best types are the spray-in-place foams. Then the foam sheets. Then batts like fiberglass and loose pack cellulose.
The sprayed in foams in general, can only be put in by contractors who have the equipment.
As with any materials in such a project, get the best that your budget will allow, because when you have more money later, it won't matter -- the floor will already be buttoned up.
Unless you're the lead dog, the view just never changes.
You might have a look at:
http://www.xypex.com
It works fine as long as the concrete doesn't have big cracks.
-- J.S.