John Sayers' Recording Studio Design Forum Archive

Steve,

I was just reading a post for another person's studio where you warned that RC on a double wall does absolutely nothing... you also said that you wouldn't hang multiple layers of drywall from RC on a wall or ceiling because it will sag.

Your explanation in that thread was that RC was for SINGLE walls and for only one side of the wall.

I guess I'm confused... I was planning on using RC (single sided for walls and double sided for ceiling) for all of my walls simply because the timber is in contact with the basement floor and with the I-beams supporting the floor above it.

It was my intent to hang 2 layers of 5/8 drywall from the channels.

Is this not going to work?

I was going to buy some RC this week and want to make sure I don't mess up what I should be doing.

Thanks,
Jim

You can put two layer of drywall on the ceiling or the walls. Go to USG's website and download their drywall construction manual to answer all your questions.

Acoustic Assemblies - Publication SA200

You may need to register to access their library.

Also, when you purchase the RC, ask if they carry different gauges and if so, buy the heavier gauge (i.e. 20 ga, 22 ga, etc)

What I hopefully said, was that using RC (or any resilient mounts) in a double FRAME wall was a waste of time, money and effort. The separate FRAMES are all the isolation you need, the only place you should use RC or resilient mounts of any kind is where there IS NO OTHER MEANS OF AVOIDING HARD CONTACT BETWEEN INNER AND OUTER LEAF of a wall or ceiling.

IOW, separate frames = NO RC.
Staggered stud frames - NO RC.
Separate inner ceiling joists with drywall only on one side = NO RC.
Common floor/ceiling joists, where drywall or other mass is mounted to BOTH sides of each joist - use RC or RSIC clips to hang the lower leaf of drywall.
Lightweight non-structural steel framed walls, with wallboard both sides of common studs = NO RC - the studs themselves are flexible enough to work as well as heavier studs WITH RC.
STructural, or load-bearing steel studs are NOT as flexible (20 gauge) so if you have reason to mount wallboard to BOTH sides of these, then RC WILL be helpful for better isolation.

I've said in several places that I'd NOT mount more than two layers of drywall on RC for a ceiling, but instead would use RSIC clips and channel because they're stronger. For a wall, you CAN mount up to 3 layers of drywall on RC; just space the RC a bit closer together.

There's a new link (probably the same as sandersd posted) to the USG manual, the link in in the REFERENCE section. I've tried to clean up most of the dead links there recently. You WILL have to "join" before they'll grant access, no biggie.

HTH; if not, ask again, but do NOT forge ahead without being sure; tearouts are a bitch... Steve