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Partially finished basement walls

Posted: Wed Jan 09, 2019 2:27 pm
by craigR
Hello everyone. This is my first post!

I have a 30 year old house that has an unfinished basement that I would like to try and finish myself. The builder has finished the exterior walls from the basement ceiling down to 32 inches above the concrete floor. The 32 inches to the floor is bare concrete with no framing. The upper finished portion of the walls consist of a one inch white styrofoam like moisture barrier followed by 2x3 framing with fiberglass insulation. Next there is a foil-like vapor barrier and the drywall on top of that.

Do I need to tear all this down and start fresh or can I somehow extend the existing walls down to the floor? If I keep the existing structure how can I connect to it and have a continuous moisture and vapor barrier? Also, can this existing 2x3 framing adequately accommodate insulation and electrical work?

Thank you

Re: Partially finished basement walls

Posted: Wed Jan 09, 2019 2:36 pm
by Shannon
Post a couple pictures please.
2x3 framing is really not enough to give you adequate insulation depending where you live so you may have to start over? The distance the framing is spaced from the foam may help if there is a good gap. What are the actual dimensions of the framing?

Re: Partially finished basement walls

Posted: Wed Jan 09, 2019 2:58 pm
by craigR
Hi Shannon. Thanks for the quick reply. I live in Montreal so the winters are usually very cold. The 2x3 studs are pressed right up against the foam with no air gap. The framing studs are spaced 24 inches apart and run 60 inches down from the ceiling.

Re: Partially finished basement walls

Posted: Wed Jan 09, 2019 4:54 pm
by Shannon
So with out knowing exactly what type of foam panel you have now or insulation in the walls this is a bit of a guess but even with the best materials you would have R15 at best most likely you have maybe R12 . Your area is likely saying you should have R17 to R21.
Personally if you can afford to do it I would recommend tearing down what you have and re doing it. This way you know what you have and that it is done well.
My recommendation is 1" XPS rigid foam insulation against the concrete walls and then a framed 2x4 wall sitting about 1/2" infant of that and R14 Roxul insulation or R12 batt insulation in the wall. Also of course you need a air/vapour barrier after that. I have many videos explaining these exact processes.