So how is this floor/wall plan?

[brettster]

Background: I am building a studio based on John's suggestions (studio) using the inside out wall design. I have decided against floating the floors because I don't expect to be recording drums very often. The floors of the rooms will not be connected except for resting on the same garage floor.

OK here is the design I am considering for building the floors and wall. What is wrong with it? Comments? Suggestions?

Also, the insulation on the wall should be 2.5 pcf correct? And how do I fasten it to the drywall.

[VSpaceBoy]

Looks right per Johns wall design.

I have seen ppl glue the insl if its the rigid, or staple it if its the fluffy with backing.

[brettster]

VSpaceBoy - Thanks for the confirmation on the wall setup. I would prefer to glue the insulation ( avoid accidentally hurting the isolation with holes) but then I would like to be able to use the fluffy insulation (cheaper).

Perhaps I could glue wood strips to the drywall and then staple the insulation to that?

Any comments on the floor construction?

[VSpaceBoy]

There is no reason that the staples should compromise your isolation. With 5/8" drywall, a 1/4" staple shouldn't come close.
But to answer, you could still probably glue the insulation. You would just have to get kraft face batts and use plenty of glue.
I thought you said you were not goin to float the floor? Well, in that pic the floor looks solid, what was the question?

Ron

[brettster]

Well, in that pic the floor looks solid, what was the question?

I was just wanting to make sure that what I came up with was workable. I've never done this (building floors and walls) before so I'm a little unsure about stuff.

Thanks for your input.

Brett

[knightfly]

When used INSIDE a wall, snugly packed fluffy fiberglas insulation compares well to the rigid board kind - however, when the insulation is exposed directly to the sound as in the "inside out" walls, then the much lower density of the batt kind of insulation doesn't do nearly as good a job of absorption. For insulation that won't be inside a wall cavity such as this, I would stay with the rigid fiberglas, such as Owens Corning 703... Steve

[brettster]

Knightfly-

I knew to use 703 or the equivalent on the inside (studio side) of the inside out wall. Are you also saying to use the 703 on the drywalled side as well? The reason I ask is that when I looked at the Leftbank studio construction pictures(http://johnlsayers.com/Studio/Pages/update_1.htm), the insulation looks like its a fluffy variety coming off a roll.

Brett

[knightfly]

No, that's not what I said - the reason you saw the "fluffy stuff" being used inside the walls (not exposed to the direct sound) is that it works, and is quite a bit cheaper than the rigid stuff.

You already had it right, just ignore me. I just wanted to make sure you understood where the rigid stuff worked better, and where it didn't matter as much.

I thought I wrote the previous post as clearly as possible, but I guess not - here's the basic rule -

If insulation is covered by wallboard, then the fluffy stuff, preferably snug-filled, is nearly as good as the rigid and it's cheaper.

If there is only a light covering, such as cloth, over the insulation, (in other words, if the studio is finished and you can TOUCH the treatment without putting your fist through wallboard) then it needs to be either rockwool or rigid fiberglas. Covering either of those with lightweight plastic will keep the room brighter sounding, and contain any fibers/dust.

Whatever cloth covering you put over that is mainly for aesthetics.

I hope that was more understandable... Steve

[brettster]

OK, glad we're on the same page now. I went back and read your post and it says what you thought it said, I was just in a different mindset when I read it at the time.

Brett