Insulating Basment Walls

[Aaron Montgomery]

Larry,

That is exactly what I did... 1.5" extruded foam panels against a block wall, followed by 2x4 studs set 1-1.5" away from the foam to allow for easy runs/changes of utilities. When finished, it all gets drywalled over (it's not legal or safe to leave the foam unprotected).

I highly suggest Dry-Lock before putting up the foam if you're underground. Also, you still need fireblocks (unfaced rock wool or fiberglass is fine) every 10' in the vertical studs, and any horizontal runs (like joist runs above) should be blocked.

This is exactly what I did as well. It's worked out well so far.

[Larry Frank]

I like the idea of using 1/2" plywood over the stud walls. However, my understanding is that if you use the foam board insulation, my building code requires a firebreak surface such as drywall.

[Steve Goetz]

Larry,
What you are suggesting is exactly what I did when I finished my entire, poured wall basement about a year ago. 1-1/2" pink styrofoam, stud wall with R-13 faced f/g insulation, and 1/2" drywall. If you seal the styrofoam with aluminum tape, it will act as a vapor barrier like others have said. Another thing that I did was to only insulate down about four feet from the ceiling because after the frost line, the ground temp. is constant. I did alot of research before doing mine and it seems to be working well so far. Good Luck

[Jim Finn]

When I bought the house in Maryland, the pored basement walls were covered with foil backed fiberglass only. I did not like the look of this so I mounted metal studs, on metal top and bottom track, attched to the floor and the floor joists, overhead, and covered the studs with drywall after installing wiring. Lost about 7" of space in the shop but it was 1400 square feet so it was no big deal to me.