basement frameout – poured cement walls
Got a lucky break last night on a furniture making call. Went to talk about building a entertainment center and was asked if I’d like to do the basement frameout, too. I immediately thought of Ed Hilton’s tag line Whenever you are asked if you can do a job, tell’em “Certainly, I can!” Then get busy and find out how to do it.
I’m quite comfortable building cabinets so there’s no problem there. My question is on framing out a basement. I’ve done framing before but never in a poured cement wall. Are they’re any special considerations when doing these? Can you use a 22 nail gun and shoot into the walls? Would drilling and Tap-cons be better? Is insulted foam a good moisture barrier or do I need something else in addition to it?
This is my first decent sized job and I don’t want to make any major screw-ups. I’d really appreciate your input, guys.. If I do good here I’ll be able to get more work out of this down the road.
(My background is cabinetmaking and finish carpentry with some remodeling on a small scale.)
Thanks for taking the time to read my post, Dan
Replies
There are special considerations for framing out basements. Find out first if there has ever been any water in the basement. Leaks and flooding need to be fixed first.
The do a lot of reading here:
http://www.buildingscience.com/
I suggest putting foam panels on the walls before you do the framing.
Others will have lots more to say here. Use the "search" function and you will find answers to almost any question that you have, and answers to a few questions that you did not know to ask...
Billy
Edited 11/10/2004 9:18 am ET by Billy
You dont have to attach anything to the wall.You can use 2.5" metal studs in front of the the wall, and fill the voids with rigid foam. If you want more insulation and prefer wood , you can stud out the walls with 2x4 and insulate with fiberglass.Be sure to solve any moisture problems first.
When we framed our basement, we used pressure treated lumber for the bottom plate. Was that overkill? You didn't mention it in your post. I'm a DIY homeowner, just in case you couldn't tell! LOL!
I think we used a Hilti to secure the framing to the floor. I guess you have to make sure there isn't radiant heat in the floor before you go nailing into it.
I'm busy doing the same thing right now Dan, framming my poured concrete basement. I'm doing it with 2X4's and - to Paula's point, using PT for the bottom plates - which is code in my area. Shooting the plates with an incredibly cheap but wonderfully effective Remmington. Whack, BAM!
Note; if using PT for the bottom plates don't forget to get coated nails. I bought a box of ACQ rated ring shanks for the nailer - using them everywhere.
My basement has no moisture issues. I'm holding the framming off the walls by just shy of 1.5 inches. Doing so will allow me to glue 2X cut offs snuggly between the studs and the concrete to reduce vibrations. I was amazed how much a single stud vibrates when knocked. (this room will be used mainly as an entertainment room; vibrations are BAD). Not using foam on the walls, just FG in the bays and sound bats in the joist cavities. 1/2" drywall on the walls, 5/8" X on the ceiling.
Nuttin but fun!
Dan
My basement has no moisture issues. I'm holding the framming off the walls by just shy of 1.5 inches. Doing so will allow me to glue 2X cut offs snuggly between the studs and the concrete to reduce vibrations
I'm not sure in understand what you're saying here. Why are you leaving your framed up wall 1.5" off the concrete wall?
Bob,
My logic - perhaps flawed, is to leave some air space between the framming - including the insulation, and the concrete wall. Doing so will ensure that if the concrete does collect any condensation on it then the insulation won't be in contact with the concrete and therefore cannot absorb the moisture from the wall. Additionally, holding the framming/insulation off the concrete will provide an air gap thus allowing for some degree of air movement in the wall.
Dan
"Additionally, holding the framming/insulation off the concrete will provide an air gap thus allowing for some degree of air movement in the wall."
But that is EXACTLY what you don't want to happen.
That air will carry moisture. And with the insulation the foundation won't be warmed from the house. So you have nice warm moist air that sneaks behind the wall and hits the nice cool concrete and condenses.
That is way I like foam. Seal it up to the wall and the warm side says warm and the moisture can't get through it in enough quanity to condense. Then build a frame for a decrotive wall infront of it.
I am not a pro. But I did this about 20 years ago and it work (but that was an applicatin with about 60% exposed concrete on 2 sides).
And in the last few years read about it many places.
Last year I finished a basement for a friend. And used 2" EXP (R-10) and sealed it bottom, sides and top (to exsisting DW ceiling) with great stuff. Then used 1 5/9's metal studs for the DW in front of it.
I understand what you are saying Bill, but I wonder how much condensation will form and, therefore, if it'll even be an issue.
To tell the truth, my head is swimming with all the recomendations/opinions; foam, VB's, foil faced vs. kraft faced, unfaced, etc.
Looks like I need to research even MORE than I already have.
Dan
;)
Well Dan then do us the favor of sharing your insights once you figure it out. I'm going to need to do this as well. My thoughts ...w/o researching it much...would be to frame up a wall using 2x4 studs and nail them directly to the concrete wall. I guess using one of those winchester powered nail "guns". Then put foam sheathing in between the studs (maybe 24" in center...i've have to check code on that). and then drywall.
Like i said though this is somewhat of an uneducated approach at this point.
Bob...it is somewhat guessy.
Fastening the studs to the concrete wall is the slowest, most expensive idea. When your framing in a basement..if you look up...you will see plenty of soft easy wood to fasten the wall frame too. It will stand very firm if you anchor it to the ceiling every few feet.
Sometimes you gotta remember the boogerin rule...."just because you can, doesn't mean you should!"
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
...."just because you can, doesn't mean you should!"
If only i could remember this at times.
So blue...do you nail to the (concrete) floor as well as the ceiling? The rest seem OK?
Yes... we fasten the bottom plates to the concrete. If were using cut nails...about every four feet with glue on the bottom too. If were shooting...then we hit it about every 2'. If the concrete is brittle...we glue and nail as little as possible.
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
OK thanks.
There are all kinds of systems that "might" work.But in basement you have a large range of amount of humidity in the air, the amount of basement that is underground, the quality of drainage and damp proofing.Now nothing will work in a "bad basement" but I feel that solid foam with a wall in front of it is the most forgiving design. Again I am only a DIY and my experience is limited. But it is the only system that I would every use. And I see more and more pro's recommending it.
If it were my basement, I would want all water problems solved, then 2" rigid foam shot and glued to the walls, with foamseal used at the bottom and the joints. I would then want metal studding used, right against the foam, then the drywall work.
Everyone has already given you great advice. The only thing I would add would be to pay attention to the draftstopping issues that will occcur. Most framers will miss this detail.
Finishing the walls creates potential fire hazards (wires, plugs, switches, etc). If you don't limit the amount of cubic feet of air, you are potentially creating a fire hazard.
Most frame walls are boarded both sides, limiting the amount of air to one bay. In a basement, with the walls held off the concrete and open access to the ceiling, you are offering enough air to get a small fire roaring...so seal it off according to your local fire departments requirements.
Heres what I've done in the past. I start with a2x6 nailed to the ceiling tight to the existing sill plate. This typically creates a solid firestop and gives me a good place to anchor my studs. Sometimes I use another plate, sometimes I don't...it depends on the ceiliing situation.
Occassionaly, there are pipes and wires running tight in the corner. I then start with a 2x4 next to the pipe and cap it all with a 2x6 holding it tight to the concrete wall. This again provides a draftstop between the wall and ceiling.
One the walls, I split the cubic volume up by draftstopping somehow, some way at the corners. Usually this will be good enough.
On of the hardest things to do is draftstop the ceilings into smaller sections. The last one I worked on, the ceilings were limited to 500 sf. That was tough...because all the mechanicals make for some challenging boogering!
blue
Warning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
Interesting that you brought up the 500' number.
Is that on dimensional lumber joist?
IIRC for open floor trusses it is required by IRC to be at 1000 sq. ft. I'll look it up this evening.
Dave
Dave, the code might have been a local building code. I don't know what the new code is for floor trusses. The last time I used them, there were no requirements to split up the ceilings.
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
Hmmmm… ok here’s what we’ve done and why.First, I want to know just how “wet” the basement really is. I look for damp spots or signs of damp spots. We then tape plastic to check for water vapor on spots at walls and ceiling. If we find signs of any water we first fix the problem. After all this we coat the basement walls with a high quality sealer waterproofer. Now we’re ready for the framing.
When we’re ready to frame I measure 5” of the walls and strike a line. I then shoot a pressure treated plate to the concrete floor. By keeping the plate to the inside of the line I have an 11/2 “air space” between the framing and the basement walls. Why? I’ve found that over time the insulation can “wick” dampness into the finished walls.
When framing I have a wall unit that is 11/2” shorter and I can lift the section onto the bottom plate. Easier then trying to beat a full length wall into place with a sledge. We shoot into the floor joists or blocking attached, if a wall runs in the space between the floor joists.
Up here in the peacable Kingdom, lots of folks strap the basement walls with 1x3's horizintally on two foot centres. (Use tapcons, stryker nails or hilti for this,) then install 2x2's vertically on 16" O.C. nailed to the 2x2's. Get the cavity foamed with PU spray foam, and while you are at it foam in the rim joist at the sills. This works slick as snot on a door handle. Of course rough in all your mechanicals, and electricals before hand. The foam will stiffen everything up when cured, and then drywall over.
Cheers,
Erwin
Thornbury, ON
dan, where are you located. I have heard in some parts of the country (colorado for one) consideration must be given to basement slabs that float up or down considerably. Slip track or some other form of plate is used to allow movement.
I use metal studs exclusively in basement framing, tho some here have me thinking of using metal track, wood studs. The metal track affords you the ability to go up down and sideways when running plate, a good idea in basements when all you see are impediments to straight framing.
Remodeling Contractor just outside the Glass City.
Quittin' Time
Thanks to all for your info. Between what I got from your replies and one old thread I dug up (the search feature worked for once) I'm ready to put together a good proposal.
To quickly answer some of you questions. Im in S.E. Pa. and the water issues are unknown. The house is under construction and will be done in Jan. They want to finish off before spring so I wont know.
Will do on the firestop. That was one thing I didn't think about. Also, the metal studs sounds intriguing. Never did it so I'll need to get more info on that. I'll try the search feature again, maybe it'll come thru twice in a row. If not, I'll be posting a ? on that.
Again thanks to all. This site is fantastic. It gives you a leg up on all the others out there that don't use the computer as a tool.
Dan
I wouldn't use a moisture barrier on the inside of the basement wall. It is better for the little moisture that may get in there to be able to breathe itself out. Waterproofing should be applied along with foam insulation on the outside of the house up to the finished ground level. If the house is at the bottom of a hill, be sure that there is a good drainage system around the foundation before taking on the job.Les Barrett Quality Construction
The most important thing noted here is to look at buildingscience.com. Search basement finish. The next most important thing is to use foam, and seal it so that moist summer air can't find its way to the cold concrete and condense.
andyArguing with a Breaktimer is like mud-wrestling a pig -- Sooner or later you find out the pig loves it.
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
I believe that quote was authored by one of our dead presidents. not sure but I think teddy roosevelt
anyway, check your local code. around here you need to provide a dedicated fresh air supply. either an air to air exchanger (which can be expensive) or circulation encorporating the above grade forced air heating/cooling system. you only need to cut into the return ducts and set up a relay that triggers when the space is occupied via a light switch.
then get 10 different opinions about how your vapor barrier should be set up and pick one.
I believe you need no vapor barrier at all. but thats another thread
hi Dan019
alot of good suggestions. i have experimented with quite a few basements, each one turning out good but the best method i use now, although not the cheapest, is to frame the walls with 2x3s and get the guy in to shoot the cavity with poly u.
i use a treated wood bottom plate and nail the wall like Blue described, bottom plate to the cement slab and top plate to the ceiling joists and about 3/4" from the cement foundation. this space will allow the foam to coat the entire cement wall with at least 3/4" behind the studs. the foam holds the studs strong and they will not bend or warp, half of the stud will be in the foam. like mentioned before, shoot the rim joist at the same time (just that makes it worth doing). no vapor barrier needed in most cases. make sure you run all your utilities first as they will be somewhat in the foam. jamb extensions for the windows. easy system. use the foundation as a guide but build the walls independent of it, plumb, straight and square.
kev
Kev advises:
> but the best method i use now, although not the cheapest, is to frame
> the walls with 2x3s and get the guy in to shoot the cavity with poly u
Interesting idea... Is the gunned-in foam dense enough? I thought the dense 2" thick poly-styrene sheets were impenetrable by water vapor -- how about the gunned-in foam? Is the cured foam dense enough or is it filled with air pockets where moisture can get trapped?
Filling the stud cavities with foam sure sounds appealing to me (if my fire district approves of the material)
-Mike
Edited 11/23/2004 2:10 pm ET by Smithers
Mike
the gunned foam is much like the "great stuff" we use to insulate around windows but the foam is maximum expansion. It is very dense but more importantly it has a smooth water proof skin that has no open air pockets at the surface whe cured. I also use it to insulate about 3' of steel beam ends that are supported by exterior walls, keeps the steel from conducting the freezing air. Just make sure everything about the wall and its utilities are how you want it because changes after the foam is sprayed are not easy. best basement system we've found yet for our climate.
kev
Kev:
Thanks for your reply. I need to discuss this option with my fire district and see if they would approve of such an application (I'm assuming the cured foam is cumbustable). My fire district is VERY strict about residential additions/finished basements but my hope is that if I cover the foam with drywall or lumber that I should be fine.
The gunned foam also sounds quite appealing above the new framed walls to coat the mud sill edge and band boards as it's a hassle insulating that area and it also seams to have significant air infiltration in that area.
Any thoughts on Icynene vs. Corbond? Would either (or other) work just as well?
Thanks again,
-Mike