John Sayers' Recording Studio Design Forum Archive

I have finished framing (used 25 gauge steel studs) and I'm preparing to drywall. Here are some questions and concerns regarding the double wall (2 independent sets of framing - leaf spring leaf. The gap is just over 8") that seperates live room and control room :

First off. I have 1/2" and 5/8" drywall. I am planning on strip laminating and screwing sheets together. I figured that in order to keep each leaf at a different thickiness I would use 5/8" (base layer) attached to 5/8" (face layer) for the live room side. And 5/8" (base layer) attaced to 1/2" (face layer) on the control room side?

Secondly, I am planning on installing all base layers with their long edges parallel to framing (studs), and the face layer with there long edges parallel to the floor? The face layer joints will be offset by 10" form the parallel joints in base layer?

Thirdly, I'm planning on caulking with acoustical sealant around the entire perimeter of the wall. Does this caulking have to be done for both base and face layers?



Any advice would be very much appreciated.

James

Hello James,

I'm sure you've read already, but cross reference with "complete section" sticky again at the top of the forum. You can also look at the pix I've recently posted under the "floating floor over basement concrete" sticky too. I used steel studs and show some of the methods I used for the walls and isolation.

As far as sealing/caulking, you want to leave a 1/4"-3/8" gap above the floor and below the ceiling as well as any corners where walls intersect. Caulk EVERYTHING on each layer. On the corners, be sure to overlap/stagger the layers.

Be sure to stagger your joints in the drywall too. Don't overlap seam to seam. First layer vertical, second layer horizontal. That is correct.


Aaron

I used 3 layers of 5/8drywall - I found that trying to screw sheets together is an exercise in futility -others may have had luck with that but I found that although it sounds great - it just doesn't work - so all the layers are screwed into the studs. The 1st layer had a lot of screws - then the next layers had drywall compund between the sheets and less screws.

Alternate horizontal & vertical - overlap all seams and put caulk between the joints of every sheet.

Works great.

I'm going to have to edit some of my posts on that thread, I've also found that the glue/lam method isn't worth the trouble since writing that.

The best way, especially when using separate frames, is to just use half as many screws for all but the last layer of drywall, alternate the orientation of wallboard for successive layers, leave 1/4" gaps at edges for each layer, and caulk each layer as you go. Using spacers at bottom and sides works good for the 1/4" gap, then once the screws are in you pull the spacers, caulk, and repeat. Always mud and tape each layer, especially where tapered edges are butted - otherwise you have a weak spot (isolation-wise) where there is a slight air gap between layers. At other joints, acoustic caulking works about the same as mud.

Any flanking from fasteners penetrating multiple layers of drywall is effectively negated by stuffing the cavities with insulation... Steve