Advice for basement wall finishing.

[bigguns69]

This is not garage related, but when I get this done, I can get back to shop/garage activities. I am working on finishing my basement. House is 10 years old with poured concrete walls and floor. The exterior side has the water proof coating and 2" foam board below grade. The basement walls have been dry the entire 10 years.

In regards to finishing off the walls, I was originally going to stud with 2x4 material up next to the concrete wall surface taking into account of alingment issues, then fill the gaps between the studs with 1" to 1.5"poly-styrene or foam board and then fill the remaining void with batt insulation. I have read on some home building forms where it is recommended to put a vapor barrior, or insulation board, or air gap between the concrete wall surface and the new stud wall to keep direct contact off the concrete. Makes sense from a damp transmittal aspect but the walls have been dry and have protection on the exterior side.

Some of my reference material from Taunton's, Fine Home Building, show 2x4 material and batt insulation directly touching the concrete walls. So I am kind of confused, but think techniques have changed over the years as well.

My reason for putting the 2x4 material against the concrete is for ease of install and if i ever need to get back to the concrete surface to do repair or modifications, I can break into the drywall, remove the bat and foam board insulation, and do what needs to be done.

Opinions from anyone that has finished off basements concrete walls or have had it done, would be greatly appreciated.

 

[tjpavlov]

Have you looked at insofast panels? I am thinking about using them in my basement. It should give you a better thermal barrier than what you are planning.

 

[97dynaglide]

I finished mine last winter.
Like you, I have poured walls and the basement was very dry. I kept the humidity down to less than 45% with a dehumidifier.

You never want lumber touching concrete, especially in enclosed basement walls.

I kept the 2x4's 3/4 to 1 inch off the concrete walls. I then had a company come in and spray foam the walls, and rim joist areas. The foam went on 2 +/- inches thick in and around the 2x4's.
With spray foam in a basement, anything over 2 inches borders on a waste of foam and money for the return in R factor.

If I were you, I would place the foam boards tight to the concrete and tape all the seams. You don't want any air to come in contact with the concrete, that will lead to condensation, then mold.
(This is where spray foam really shines, it totally seals off the concrete wall so no moist air from the basement can get to it).
Then I would install the wall studs tight to the foam boards or as close as possible to keep your walls square and plumb.

I left the areas between the studs and foam empty so I could run wires easier.

 

[mepooooo]

You can learn more for basement from link below:
http://flolly.com/category/home/basement/. Thank you

 

[BPJOOP93]

I glued the foam board to the walls and then studded and then put the fiberglass insulation in between. worked great and the basement is about 7-10 degrees warmer than the upstaires.

 

[rust buster]

I glued the foam board to the walls and then studded and then put the fiberglass insulation in between. worked great and the basement is about 7-10 degrees warmer than the upstaires.

I second this, it worked great for me.

 

[rct]

Essentially the two gentlemen who recommended foam bonded to the concrete are in line with the best available recommendations. You might find the link below on basement insulation recommendations and some cons to fiberglass batts helpful reading. On a side note, be sure you have no water/moisture problems in the basement, if so, address those first before you finish the basement.

http://www.buildingscience.com/documents/reports/rr-0202-basement-insulation-systems

 

[cgall]

Batt insulation can go up against dry concrete, and need only come down 3' below grade. I always put my vapor barrier up after the insulation, between studs and drywall. If you have metal HVAC ductwork thru your basement and plan to enclose it in drywall or paneling, you need to wrap the ductwork in plastic sheeting to prevent it from sweating in the summer.

 

[911mike]

1" tounge and groove foam glued to the wall tape all seams. Frame as close as you and still keep a plumb wall. I don't recommend fiberglass insulation. Spray foam is best but is 2-3 times the cost. Don't forget the rim joists. Those are major area's for air leaks. I use 2" foam cut to fit between the joist and then seal with great stuff.

 

[LennyTheLizard]

I have a guy that works for me that is old enough to be my dad. I think he can fix anything. Best piece of advice he ever gave me:

"There's two kinds of basements, ones that leak, and ones that are gonna leak"

Of course, I didnt' listen to him and completely finished my basement with drywall and some real nice carpet. Because it was completely dry and had never leaked before.

Guess what: We go a rainstorm a few years back and it rained 13" in 24 hours. It leaked, after that it leaked a couple more times. You wouldn't believe how that insulation wicks up the moisture.

I would take the advice of others:
Put foam board insulation against the concrete.
I would use metal Z furring strip to attach your drywall - no wood studs needed.
Keep your drywall 1/4 - 1/2" off the floor
Use flooring that won't hurt to get wet - ceramic tile, bare concrete, vinyl tiles.

 

[#1SomeGuy]

Frame a little bit off the concrete with 2x4's, depending how straight your wall is but keep at least a 1/4" off (1/2" is better). Bottom plate should have sill gasket under it, top plate can go to your floor joists. You don't need a vapor barrier between the concrete and framing, it goes on the warm side over the insulation/studding.

Insulation, spray foam is best but quite expensive. I was quoted around $2500 for about the 800 square feet of wall space in my basement. I did it with roxul comfortbatt (R14) for around $600 including vapor barrier. It's plenty warm and if I ever need to get at anything I'm not totally screwed and having to tear out spray foam and somehow trying to get that fixed.

Also, I did dricore as a sub floor which recommends you frame on top of it, keeps the bottom plate off the floor and gives an air gap above the concrete.

Here are some rough pics of what I've done (don't mind the mess):