where does rc go in the construction process.

How thick should my walls be, should I float my floors (and if so, how), why is two leaf mass-air-mass design important, etc.

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notbradsohner
Posts: 9
Joined: Wed Mar 31, 2004 7:04 pm
Location: ohio

where does rc go in the construction process.

Post by notbradsohner »

Hello,

I am putting up a new wall for my stuido soom seperating the control and iso room. Now, i already framed it with 2X4s, not floated, which was a big mistake right there. I should have plenty of mass, but my question is where to put RC? Does it go closest to the bass source (control room) or towards the isolated part (iso room). I plan on building as follows.


CONTROL ROOM>5/8 drywall>1/2 homosote>studs with rockwool insulation>limp vynl>RC>1/2 drywall>5/8>5/8

what do you think?

thanks
knightfly
Senior Member
Posts: 6976
Joined: Sun Mar 16, 2003 11:11 am
Location: West Coast, USA

Post by knightfly »

I have very little use for homosote in walls, another layer of sheet rock is better for isolation - the limp vinyl is 'way overpriced and under-tested. RC can handle 3 layers but not all brands are capable of that.

As to which side gets the RC, I'd put it on the side that's LEAST likely to ever have something you want to hang on the wall, so probably the ISO side - performance-wise, it's no difference - a wall will have the same transmission loss either direction.

If you have the space, and especially if you will have a window in the wall, you're much better off NOT using RC and instead putting up double frames, increasing the air gap and better isolating the two leaves of the wall (wallboard only on one side of each frame) - for inside walls, regular house insulation completely filling the cavity is as good as rockwool or 703, and cheaper/easier to find.

IF you can't use double frames, put the RC on one side with two layers of sheet rock - put 3 layers of sheet rock on the other side, caulk each layer as you go, setting the sheets on 1/4" spacers on the floor - fasten using half as many screws each direction as normal, do this for each layer except the final one which gets full amount of screws - pull your spacers after fastening each layer, caulk, and repeat. Stagger ALL seams so they don't leave cracks - minimum offset 2 feet. First layer on RC goes vertical, second layer horizontal. Be sure to use masking tape or similar for marker strips around the perimeter so you can mark where RC's, studs, and each layer's screws will go. No screws into RC within 2" of stud locations so you don't "short out" the RC. Bottom row of RC should open down, all others open UP. Any other way and the stuff will sag with the weight and may touch the frame eventually.

Check the "complete section" sticky at the top of the forum page, I probably forgot a couple things... Steve
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