John Sayers' Recording Studio Design Forum Archive

Does anyone know of a good way to make sure a good seal is obtained around the individual sheets of plywood on a floating floor?

I'm building a floating floor out of 2 sheets of flooring, either particle board or plywood.

It seems silly to me to spend a lot of time making sure the walls are nicely sealed and airtight, then to have small cracks around each sheet of flooring.

Sealant might work but I'd need to use a damn lot of it.

Also, I was planning on having a reflective floor and an absorbant ceiling. Plain plywood isn't a very nice finish surface for the floor.

Should i just carpet it and leave the ceiling reflective? Or does anyone know of a asthetic, affordable floor finish to use?

With only 2 sheets, I assume the joint in on the long dimension. I would use sheets of 1 1/4" subfloor ply, which has a tongue on one long edge and a groove on the opposite. I believe this is available in OSB too, but probably only 3/4" thick. But in case I misunderstood you, and you meant 2 sheets thick, as you mentioned using LOTS of sealant, which one joint wouldn't use hardly any, I would still use the T&G subfloor ply or OSB, and then put in a laminate wood floor(after walls are done). For coverage of 2 sheets, the cost would be very small. For larger areas, it still is pretty reasonable.
Forget the carpet. Of course, thats only my .02.

fitZ

Yeah, sorry you misunderstood.

What I meant was that the floor would be 2 sheets thick. The room is about 14 square metres (roughly 3.5m by 4m), so I was considering using six sheets (1.2 X 2.4m) to cover the floor, then another six sheets for a double layer, and trying to stagger the joins.

The only problem is sealing the cracks between the sheets, and the fact that the cost of these 12 sheets would be inconcievably expensive. (Over $1000 AUD - they're $40 to about $90 each depending on thickness and material).

Brad, you could probably seal between sheets with gypsum "mud", if that's cheaper in OZ - what's vinyl sheet flooring cost in your area? it's about the least costly here of anything, although some people hate it -

You ARE planning on using insulation between joists to damp the floor panels against ringing, right? Steve

Six sheets, two sheets thick. Depending on how you orient them, thats a maximum of 4 short and 6 long joints. And since they are tight joints, I don't see using more than 6 tubes. And then the laminate floor has a thin foam underlayment that it floats on. That would help seal it too I believe. OR, maybe you could use a router and spline bit, and spline every joint with a 1/4"x1" masonite or ply spline. Then glue them with yellow carpenters glue. I've done this many times on panel projects. No matter what, it is not that big of a floor so I think the cost of sealant would be negligible compared to the shiething. Of course, every cent counts to me also.
fitZ

Steve, is gypsum mud another name for the adhesive used to stick plasterboard to wooden studs? Would regular construction adhesive serve? Which out of the two do you think would be better?

Does the below picture look any good?

It is 19mm yellowtongue particle board, with a thinner layer of MDF (8-10mm) over the top. The MDF comes in different sizes to the particle board so it will be easy to stagger ALL the joins.

On the end joints of the particleborad, where there is no 'yellowtongue', i could do as cadesigner suggested and use a plywood joining strip.

In your opinion, do you think this floor would suffice?

Im struggling for room height, so i dont want to use too thick a floor.

By Gypsum mud, i think he means the putty that you use to cover the seams, screws, and corners when drywalling.

What you're refering to is called plaster here.

White powder, mixed with water?

Joint compound is the trade name. It is used to cover the paper or fiberglass tape OVER the gypsum board joints, not as an adhesive to fasten them to studs. You can purchase it pre mixed, or as a powder, but it is different than plaster. Plaster is a different compound. I believe gypsum board is mixed with the plaster compound, but I could be wrong about that. Sorry Steve if I'm stepping on toes, but I know your busy so I try to help. I'll stay out of your way with the technical stuff.

fitZ

Ah ok, thanks.

'Joint compound' as it's called in the US is just refered to as plaster here. Or more specifically 'Basecoat' and 'finishing compound'. (As well as cornice adhesive).

It seems very unusual to me, to put this stuff (joint compound) in the floor joints...I thought that they'd develop hairline cracks after being walked and played on for a fair amount of time.

Hello Brad, I can't speak for Steve, but I bet he was only thinking in terms of budget filling, and THEN covering with a roll out vinyl finish floor, which would seal it once you applied the adhesive. But again, I'm only guessing. Actually, I shouldn't try and second guess
Steve at all, so I'll butt out.
fitZ

Not at all, Rick, looks like you guys have it covered pretty much - thanks for the help, I couldn't even access the site for the last 36 hours or so... Steve