RC-1

So... I talked to my drywall contractor today. He said "I wasn't planning on mudding and taping the first layer"... wow... glad I talked with him. Looks like I will be caulking (with oc-175) the perimeter and mudding/taping the sheets on the first layer myself. I also asked him about the RC-1 usage. I asked if he was going to be spacing according to manufacturers specs and he told me "yep... 24 inches on center... I'm using a 'heavier gauge - but its still RC-1' " Does this sound right? I'll be hanging two layers of 5/8 inch drywall off of this for floor and ceiling, so with my 8 foot high walls, that means he's only putting 4 strips of RC-1 on each wall. Jim (Velvet Elvis)

That was how I did the walls in my control room...24 OC. The ceilings though...(can't remember...but it was either 12 or 16 OC.).

Aaron, Ok... did you hang two layers of 5/8 on top of it? I only have 8 foot high ceilings, so that means I'll only have 4 RC-1's per wall. I'll have to ask if they are going to double up the ceiling a little more for safety's sake. When the contractor told me he's using heavier gauge RC-1, does that make sense? I thought RC-1 was RC-1, but I could be mistaken. EDIT: One thing I noticed in looking at your thread is that you mentioned RC-1 in your build thread, but he stuff on the walls of the control room looks like RC-2 (double legged resilient channel). Can you confirm that? Jim

I had one 10' x 10' shear wall that I applied a total of four layers of drywall onto, over 3/8" OSB. This is my "middle leaf." (Unfortunately it has to be a three leaf wall.) I actually did not bother taping. I only used one layer of joint compound (mud) and I did not sand it down. Am I worried about cracks over time? No... I can't see it mattering. I was careful to stagger my seams so that no two adjacent layers had seams aligned. --Keith :mrgreen:

Keith, See that's interesting... I'm SOOOO freaking scared of messing this thing up that I panic when a contractor says that they aren't going to do something I think they should. Now... of course I don't assume that they know what they are talking about (countless stories are found here at the site that confirm most contractors don't), but at the same time I might be being too paranoid. Let me as this along with the same questions (about weight on RC-1)... did you all caulk corners? or did you mud and tape? Jim

My control room walls are and ceiling are all 2 layers of 5/8" drywall. All RC that the drywall is attached to IS RC1. The only stuff that looks like RC2 is the hat channel I used between the walls to hold in the insulation. ALL CORNERS are caulked. Especially where they stagger in the corners, there's a bead of caulk on each layer where they overlap. All layers are sealed at the bottom as well as the top. SEAL EVERYTHING. Including door jams and window frames when the time comes. I taped and mudded each joint on each layer. I did not sand...wasn't necessary. But you must seal them at the least. And most important...stagger your joints from layer to layer. Hang one vertical, and one horizontal.

Ahhh.. that makes sense. What did you do about the ceiling and such above your control room? I was looking at the pictures and it looks like you had a similar situation to what I have - odds and ends of mechanical (water, heating etc) tucked up in the rafters which makes it difficult to put a layer of drywall up against the subfloor above (assuming you are in a basement or something with a floor above it). I'm wondering if I fill the cavities with Rockwool, and do as good of a job as possible sealing the inner leaf (control room walls) if the isolation will be adequate with w layers of 5/8. Thanks for you help, I truly appreciate it! Jim

If you need additional isolation, you may want to consider beefing up w/ some drywall against the bottom of the subfloor upstairs between the joists. Several people here have done this. You may even consider Green Glue between the layers of drywall as well. Are your walls tied to the structure or decoupled? Are you also in a basement or do you have good height above you where you can build a separate framed ceiling, completely decoupling from the structure above?

The walls are tied to the structure, so I'll be using RC everywhere. It is indeed a basement. I've got some problem areas (like where the I-beams sit on top of the concrete that I'm not sure how to treat. Its above the ceiling line of where the studio will be, but its all inbetween the 1st leaf (studio ceiling) and second leaf (subfloor of the room above). Lots of things like air-returns are crafted into those spaces too, which means even if I cover some of the subfloor with drywall, there are still tons of weak areas. I can take some pictures if it would help to explain what I'm talking about. Jim

Yeah, give us some pix...

Aaronw wrote:

If you need additional isolation, you may want to consider beefing up w/ some drywall against the bottom of the subfloor upstairs between the joists. . .

Just be sure you don't overload your joists! :shock: Don't miss the "Safety During Demolition, Construction" sticky thread, including the post about the span calculator and the link to understanding loads and span tables. --Keith :mrgreen: