Going to finish the basement soon, and can't decide which way to do the walls. There are pros and cons for using furring strips and a product like DOWs STYROFOAM for insulation, or a 2x4 framed wall with standard fiberglass insulation.

If I use the furring strips I won't lose much in the way of floor space, the vapor barrier is built in and the installation is easier.

Has anyone used this method?

I live in the Chicago Area, and the house is less than a year old. The basement has solid concrete walls.

Any opinions or experiences would be great.

David

 

Go the 2X4 wall dont put furring strips on the wall. The 2X by is better for the insulation and also for running the electric. We hang V/B on the cement walls then the 2by 1" out from it R 13 in the studs a poly over that then the drywall. Dont forget to put insulation up in the joist on the sill plate all around the home.

ED

 

I think I am leanng towards the 2x4 method. As for the sill plate, the builder was actually nice enough to put that in for me!!!

Any reason other than the electrical your against the furring strip method? I have seen R values for the foam method close to that of fiberglass.

Thanks for the input!!!

David

 

ciphyre,

I'll insert my 2 cents worth here and say that Ed has it right on! This should clarify his reasons,

1. If you are just using 1 1/2" rigid and furring strips - A. You need W/T strips to protect the wood. B. The strips can be adhesively applied but they must be solid - mechanical anchors may have to be used to insure that if shelving is installed it will hold. Problem with this is, the penetration into a sealed concrete/masonry surface is damaged and subject to leaking. C. Any electrical boxes will have to be shallow - sometimes makes it hard to wire. D. You must use a fire retardant material over this as per Code.

(Most books, articles about rigid and furring strips fail to say anything about the use of W/T and this will get destroyed and be a good source for mold/mildew with the slightest hint of moisture)

2. Alternative which does add cost is to apply full rigid sheets to the concrete/masonry walls, adhesively applied, then place frame wall against the rigid, then insulate between studs and cover with drywall. The Rigid insulation does then act as a the vapor barrier. Do not tape/seal the seams. This allows it to breath and dry up any condensation that may form. There is rigid insulation out there that has wood strips embedded in it to aid in construction but overall costs may be too high to justify its use.

So here is some more stuff....

W/T is wood treated. International Residential Building Code says "it must be used whenever wood is in contact with concrete and/or masonry". Check it out with your local inspector. This would also include furring strips applied directly to a vertical block wall unless you use the vapor barrier behind it.

If you are considering using 2x2's as furring strips I can only give you my 2 cents worth and you decide;
A. Are you going to have electrical in the walls? Short depth boxes make it difficult to wire. 2x4's would be better. B. Are you planning or foresee hanging shelves or cabinets on the exterior walls? Not alot of strength and may be subject to splitting easier than 2x4's.
C. I personally can't seen how 2" will make a difference in conserving space when you consider the hassle of doing electrical or other carpentry issues.
D. Depending on what you are talking about when it comes to the pre-cut polystyrene, the white foam board, which is the molded expanded polystyrene (MEPS) only is available in R-2 - 3/4" thick, it only costs about $5 per 32 SF. The better quality with R-7.5 is the pink foam - extruded expanded polystyrene (XEPS). This is great stuff but costs more.

Just a note, when you use NON-W/T stock as the 2x2's or 1x3's as furring strips, you have to place a vapor barrier between that and the block wall - you have to attached the furring strips to wall somehow, right? You can't adhesively apply them, you have to use a ramset - this obviously has drawbacks...you just put a hole through the poly making it useless which in turn starts the problem with moisture touching the wood. Second, is if you used W/T or Non-W/T stock and have a waterproofing sealer on your block walls, you just penetrated the block, puncturing the seal coating that was suppose to stop water/moisture...creating possibly a worse problem....water that fills the concrete block cores starts to drain out or will leak in heavy rains. Just thought I'd bring this up. I would do 2x4 walls with R-11 or R-13, insulation would cost about $.02-$.03 more per square foot than the white foam and be better all around. Leave the walls out 1" from the block when framing, apply your poly over the studs apply the drywall and be done. You'll have no problems then.

By the way, some municipalities do not allow furring strips to be applied directly to masonry surfaces. Check with your local building authorities.

Hope this helps!