What is the best way to float a wood floor?

jeronimo · Post by **jeronimo** » Thu Aug 07, 2003 2:34 pm

I can't afford to make a concrete float... so how can I make a wood floor floating and having double brick walls?

giles117 · Post by **giles117** » Thu Aug 07, 2003 10:48 pm

Hmm, I am sure Steve has a mouthful for this one, My concern would be the weight the bricks would impose on that floated wood floor. But My best suggestion for floating this type of floor would be the designs you have seen

<img src = "http://www.saecollege.de/reference_mate ... s%202..gif" >

Where you see Neoprene Pads, use a higher durometer Neoprene. I'd suggest 80. And do not use the Pucks you have seen, but rather a full neoprene strip the length and width of the studs you are laying. And at the edges of the floor underneath where the walls will be built, I'd run double studs instead of single studs, OR use 4" x 6" thick Deck studs. This is assuming you are doing a 2x6" Joist network throughout the rest of the floor.

Bryan Giles

Update-----

Ok, now that I read another thread

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=521

I recommend you do not try to place a BRICK wall on a Floated wood floor. If I understood your question correctly.

Read that thread and they will tell you why.

Build the brick wall outside the perimeter of the floated floor, Read johns SAE site

http://www.saecollege.de/reference_material/index.html

And follow the guidlines listed therein under construction, walls/floors

They will not steer you wrong. If cost is the issue, it is worth it to spend the extra money and do it right.

jeronimo · Post by **jeronimo** » Thu Aug 07, 2003 11:50 pm

yeah giles, you understood it right... I wanted to know if I could build the wall OVER the floated floor (but I always thought it couldn't handle it)...
But it's fine, thanks for your fast response... I'll check the other posts later tonight...
Thanks!!!!

knightfly · Post by **knightfly** » Fri Aug 08, 2003 2:42 pm

Jeronimo, the double brick walls makes it a little harder but still doable - Ideally, you would float the inner brick wall on a concrete slab, but if it's too expensive you would use either ½” neoprene or Auralex U-boats (auralex.com) to float 2x4’s on 24” (600mm) centers, put at least ¾” (20mm) plywood, then Celotex or Homosote, then another layer of plywood and finally your floor covering of choice (not carpet) - be sure and run a border of the Celotex/Homosote around the inside of the inner wall, slightly taller than the finished floor, BEFORE you lay the floor, so the floor can’t touch the wall directly. Before putting down the first layer of plywood on the floated 2x4’s, you should put fiberglas or mineral wool between the joists. A black poly vapor barrier under the whole thing is a really good idea in almost all cases too. Two layers of 6 mil (.25mm) does the trick. Don’t make the mistake of putting moulding around the inner wall and fastening it to both the wall and floor, or you just wasted your time…

Since the brick walls will be quite stiff compared to wallboard, You would still need to find a way to decouple the inner wall, either sound board and gypsum or Resilient Channel and gypsum, etc … Steve

giles117 · Post by **giles117** » Fri Aug 08, 2003 10:00 pm

That clears it up for me. Guess I misunderstood what you guys were saying in the other thread.

Bryan Giles

But I have this Q Steve, wouldn't the weight of the bricks be an issue with the Neoprene being spaced so far? Wouldn't it have the potential to bow the wood stud evn though you use the flooring material to "stiffen" it some? I'd do it no less than 12" O.C. with a 2"x1.5"x 1/2" Piece of Neoprene pad at those centers. And what about the Durometer? This is a lot more wieght than a Drywalled Wall? I was thinking 80 would be a little better than just going 60

Just Curious.

knightfly · Post by **knightfly** » Fri Aug 08, 2003 10:23 pm

Sorry I wasn't clear on that guys - What I was saying, was that you would build the floated floor INSIDE the INNER brick wall, being sure to use soft surround such as Celotex between the INNER wall and the floated floor, so that you don't SHORT OUT the floated floor against the inner wall -

What I am NOT saying, is that you should put heavy brick walls on a wood floor. If that's what you want to do, the floor needs to be at least 3", preferably 4" CONCRETE, floated with something like the RIM system from Kinetics, and with EXTRA support pads around the perimeter under where the wall goes.

Hope that's clear enough... Steve

giles117 · Post by **giles117** » Fri Aug 08, 2003 10:27 pm

You know I was scratching my head on that one Steve. LOL

I am no carpenter, but My Wife owns a Construction Contracting Business (not physical, but Job estimating and coordination, and having done a ton of DIY stuff since i was 12 I had a small clue that that was a bad idea, but as you say......Tried and true techniques will Never steer you wrong.)

Thanks for the clarity.

Bryan Giles

(Now i need a swim!!)

jazzman · Post by **jazzman** » Tue Aug 12, 2003 7:36 am

knightfly wrote:

A black poly vapor barrier under the whole thing is a really good idea in almost all cases too.

Steve, I know you've had a lot of paradigm shifts lately

but here may be another one:

http://www.buildingscience.com/resource ... ystems.pdf

A concrete slab floor that's dry now may be dry precisely because it can breathe. If it can't breathe, what happens to the moisture that's in all concrete?

Another website, www.dricore.com strongly recommends leaving at least 1/4" airspace for the concrete to breathe.

So, what's right?

Lee

knightfly · Post by **knightfly** » Tue Aug 12, 2003 10:52 am

Lee, thanks for catching that - when I read your quote, I had to go see what the context was. That entire statement should have been worded better.

If the concrete isn't OBVIOUSLY wet, I would put the vapor barrier OVER the insulation/floated frame.

If, however, the concrete is wet enough that a sump pump is necessary, then it might be better to forego the U-boats for flat pucks, use pressure treated lumber, and lay the vapor barrier just UNDER the frame, pulled snug so it leaves an air gap where the pucks are. Then you could put the insulation on TOP of the vapor barrier and finish the floor. In that case, you'd probably be better leaving the concrete open to circulation, and building a double-leaf floor ABOVE all the moisture. It could get to be a tricky project.

You definitely, where concrete is involved, need to allow for breathing. Sorry for the mix-up... Steve