Basement: stud wall against XPS, remove or not remove furring strips
I’ve been in my house located in Maine for about five years now. Shortly after moving in, I put 2″ of XPS on the basement walls, attached with foam glue and furring strips 1x2s with 3-1/4 tapcons. I had planned to eventually attach drywall to the furring strips.
I now changed my plans and am going to stud wall my basement rather than drywall to the furring strips. I will be putting Roxul into the stud cavities. I also plan to 1″ foam the basement floor followed by Advatech OSB.
My question is this. Do I pull of the furring strips and place the stud walls flush against the the 2″ XPS foam or do I put the stud walls flush against the furring strips leaving 3/4″ (thickness of the furring strips) gap between the stud wall and the foam. My concern is pulling all those tapcons which essentially penetrate one inch into the concrete wall, not filling those holes and possible water intrusions from those holes. To date my basement has been dry.
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Replies
You can go with a 2x3 stud wall 1/4" away from the furring strips. This lets you use standard batts and have no gap to the foam (which you want).
Just make sure you drill your holes for wiring near the back of the studs or put nail plates.
Hi Brian.
I don't think it matters so much how you do this (I like Akos's suggestion above). Whatever you decide, don't leave an air space. Install insulation from the face of the stud wall all the way back to the rigid foam.