Finishing A Basement

[Irish]

Morning gents,

I'm in the very preliminary design stages of finishing off my basement and I'm looking for some input & advice. The basement is completely unfinished - cinder block wall construction (already applied drylock), open floor joist ceiling with a min clearance of about 7' to the bottom of the floor joists, & a concrete floor that's been painted. I'm in central NJ, so we get the full swing of temperatures and seasons. The basement is always a little cooler than the rest of the house (say about 65-75 F in the summer, 60-65 F in the winter) and I run a dehumidifier in the spring/summer months as it gets a little damp from being undergrade. Currently it's used for my workshop, laundry, and a man cave where I host monthly poker tourneys. The finished portion will serve as a man cave and additional space for the kids to play once they get a little older (son is 2 and we have another one on the way).

I'd like to sheet rock and finish the walls, and I'm bouncing around with regards to how I should go about this. A few friends/relatives and websites recommend using furring strips - say 1x2s laid flat against the walls, foam board insulation between furring strips, plastic vapor barrier, then sheet rock. I'm also thinking of going with typical interior wall construction - 2x4s @ 16", foam or fiberglass insulation, plastic sheet then sheet rock. Obviously this will reduce the area a little more, but I'm concerned with fitting electrical boxes for plugs/lights with the thinner furring strip walls.

Anyone have any insight, pros/cons of either method? Thanks!

[mackel46]

I like the 2 x4 method. Using the furing strips you are going tohave to nail into the cinder blocks which can crack and diminishes you water tight walls. Plus with the 2 x 4 you can add thicker insulation and running wires is much easier.

[Shadow]

Second the 2x4s. That's how I did mine. This allows you to use all commonly-found parts for electic, cable, phone, network, etc. You attach the walls to the floor and ceiling and you're not nailing/drilling into cinder block.

[morningwood]

I did my walls with 2 x 3's, plastic barrier, insulated and then normal dry wall.

My unfinished cellar was small height wise (~ 6 3/4') and I wanted to get as much space as I could. you can still put up the plastic barrier, run wires and insulate as needed. I would highly recommend insulating the ceiling for noise reduction and from there you can put up 1" x 3" strips, 12" C to C and put up the armstrong ceiling squares (minimun reduction in loss of height).

something to chew on.

[morningwood]

As far as using furring strips, If your walls are not flat and straight (none of them are but some are horrible) the worse off they are the worse they'll show. I was able the level vertically using the 2 x 3's

[Trann]

Although I came across the idea of furring strips on the basement wal, everything I've read/heard says wood against concrete is not a good thing unless it's pressure treated: both are porous and water (even vapour) loves porous, so you'd only do so with the bottom plates of your walls (even better, there's a thin foam that can be used to separate your bottom plate from the concrete floor). To save studs from decay, build your 2x4 interior walls away from the exterior wall. I've seen two approaches here: an air gap between the exterior wall and your stud walls (as I did) with fibreglass insulation and a vapour barrier, or interlocking foam board right up against the concrete (glued or nailed, tuck taped together, no apparent need for vapour barrier because the foam does that job) and your stud walls up against that (I can't comment on this method).

One recommendation I will wholeheartedly offer: finger-joint studs. They are made from recycled 2x4s, are a bit cheaper and -- most importantly -- all seem to be ram-rod straight (unlike regular 2x4s which can be warped, bowed, and/or twisted). I never once had to deal with a bad board and when I was done, it was a glorious run of laser-straight (yes, I ran a laser over them) studs.

[mikeneron]

or interlocking foam board right up against the concrete (glued or nailed, tuck taped together, no apparent need for vapour barrier because the foam does that job) and your stud walls up against that (I can't comment on this method).

This is the way to go.

Lay 1" Extruded Polystyrene Insulation (foam) on the floor and glue and tuck tape every joint. Leave 1/4" expansion around the room and then spray foam that expansion. When you spray foam the expansion, then you put up the wall which is 2" Extruded Polystyrene Insulation (foam). Use PL 300 in dabs on the concrete wall to hold the foam in place. The foam has lap joints so they overlap each other. Again each joint is glued and then tuck taped including the inside corners.

Then you put down 5/8" tongue and groove plywood and tapcon that into the floor. Then you can build your 2x4 walls right on top of the plywood and they will sit right against the 2" foam. Then put batt insulation in your framed walls and then drywall over that. No need for vapor barrier.

The whole idea is that the whole outside wall and floor will have foam on it so it stops anything to do with moisture buildup.

Hope that makes sense.

[Irish]

Thanks for all the feedback guys! My initial plans were to go with the 2x4 setup, but a few "handymen" have been pushing those furring strips. I had my doubts, and I think you guys have further confirmed that.

This is the way to go.

Lay 1" Extruded Polystyrene Insulation (foam) on the floor and glue and tuck tape every joint. Leave 1/4" expansion around the room and then spray foam that expansion. When you spray foam the expansion, then you put up the wall which is 2" Extruded Polystyrene Insulation (foam). Use PL 300 in dabs on the concrete wall to hold the foam in place. The foam has lap joints so they overlap each other. Again each joint is glued and then tuck taped including the inside corners.

Then you put down 5/8" tongue and groove plywood and tapcon that into the floor. Then you can build your 2x4 walls right on top of the plywood and they will sit right against the 2" foam. Then put batt insulation in your framed walls and then drywall over that. No need for vapor barrier.

The whole idea is that the whole outside wall and floor will have foam on it so it stops anything to do with moisture buildup.

Hope that makes sense.

I definitely want to look into this some more for the walls. One quick clarification - the 1" foam is insulating the floor, right? Assuming I'm not covering the concrete floor, I can skip that step and just use the 2" foam on the walls. I don't think I'm going to mess with the floor at this point - while I'd love to insulate it and throw down a tiled/pergo floor, I don't want to reduce the clearance.

[vtpoker]

If you get more than a little moisture in your basement (I've watched some of the great floods in Jersey the past couple of years.), you might want to elevate your studs off of the floor, allowing space for any leakage to run underneath them rather than run up your walls.

[mikeneron]

If you opt to put the bottom plate for your walls against the concrete floor, make sure to use pressure treated wood for it and also put a sill gasket in between so the wood isn't directly touching the concrete. I would recommend using the method that I posted though and then go with a drop ceiling such as in the link below. How much space do you have to work with between the concrete floor and the floor joists above?
http://www.ceilinglink.com/index.html

[Trann]

sill gasket
That's the damn word I was thinking of.

I used PT but didn't do the gasket; I've seen the gasket used with non-PT but wished I had remembered because I'm all for redundancy.

http://www.ceilinglink.com/index.html
FTMFW!

I bought gobs of this product over a year ago when the dollar was strong and I'm only now getting started with it. One thing I was happy to see when I talked with the owner is that he created a C-channel piece. I'm attaching my perimeter runs using C-channel to the ceiling rather than L-channel to the walls because my walls float. It was a perfect solution.

[Irish]

How much space do you have to work with between the concrete floor and the floor joists above?
http://www.ceilinglink.com/index.html

Cool, thanks for the link, all I've seen so far are those drop ceilings that just kill your overhead clearance. I've got 6'-10", concrete floor to bottom of floor joists above. Definitely will use PT wood for the bottom plate and will look into the gasket.

[Irish]

Bump - In doing some more research I found a couple of informative resources.

First is what looks to be a nice little step by step tutorial for insulating basement walls. It's not terribly detailed, but has some good pictures:

http://www.homeconstructionimprovement.com/2008/11/how-to-insulate-basement-walls.html

An interesting tip from the site - use a piece of composite decking like Trex between the bottom PT sill plate and the slab to prevent any wicking of water into the wall in case there happens to be a small leak at the base of the wall.

Second is an article on Basement Insulation Systems published in Building Science Corporation. I haven't finished reading it, but it's been an interesting read so far. It may be a little on the technical side for the average DIYer but there's some good information on how & why the industry has moved from fiberglass insulation to foam and how it relates to moisture, mold, and energy conservation in below grade basements:

http://www.eere.energy.gov/buildings/building_america/pdfs/db/35017.pdf

[MisterShark]

I checked out that ceiling system mentioned previously in this thread and found this method (http://www.armstrong.com/resclgam/na/ceilings/en/us/prod_detail.asp?itemId=44552.0)way easier and likely cheaper.
They're ceiling tiles simliar to the ones you drop into a track for a drop ceiling except they're tongue-in-groove. Simply measure, chalk line, and woodscrew some reasonably straight 1" x 3" x 12' (or whatever length-wise) furring strips to your rafters and then staple the first tile into place. The next tile gets tongue-and-grooved into the first, lather/rinse/repeat.
When all's said and done you've lost about an inch and a quarter total headroom.

One thing: just check the level of your rafter-to-rafter transitions with a long-ass level and shim where necessary.

After stapling everything in place you can roll em with whatever color paint is desired and caulk any seams that may need it.

I put some R-19 (or was it R-13) inbetween the rafters for some extra sound proofing, plus the tiles have an acoustic insulating effect of their own, and it worked out nicely.

I'll take a few pics and edit this post with em later.
For that matter, Matt: you can swing by if you'd like and I'll show you the end result first-hand. My father-in-law and I also completely did the lower level on my place, starting from nothing but poured concrete foundation.

Here are the pics. Keep in mind how these were taken: me laying flat on the floor looking up or in some other unnatural angle, at night with a flash, so certain seems will be visible due to these conditions but invisible under normal circumstances.
http://i20.photobucket.com/albums/b201/MisterShark/Misc%20Pics/P1020001.jpg

http://i20.photobucket.com/albums/b201/MisterShark/Misc%20Pics/P1020002.jpg

http://i20.photobucket.com/albums/b201/MisterShark/Misc%20Pics/P1020003.jpg

http://i20.photobucket.com/albums/b201/MisterShark/Misc%20Pics/P1020004.jpg