Author Topic: RC2 installation help  (Read 5732 times)

HokieMan

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RC2 installation help
« on: October 24, 2011, 07:41:40 PM »
I'm soundproofing a basement. Two of the walls are exterior (underground) the other two are next to rooms we use. The ceiling was exposed joists. I've installed:
- quietrock in the walls
- pink insulation in the ceiling joists
- two layers of a barrier (black roofing material) and taped (with foil tape)

My question is about the RC2 channels. I've read some conflicting instructions online. Right now I have the channels going all the way perpendicular from one wall to the other. I've read stuff online saying that you should stop the channel 6 inches from the perpendicular wall. Should I cut it short? It seems like then the drywall at the ends would just be flopping down and over time bend. Am I missing something? Also, I butted up the RC right against the parallel walls. I figure the lip of the channel would give enough gap so that the ceiling drywall doesn't hit the walls.

I can post pics tonight to show what it looks like. Thanks in advance!

Randy S

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Re: RC2 installation help
« Reply #1 on: October 24, 2011, 10:20:13 PM »
You should leave about an inch gap to the perpendicular wall, or the most you can do with out creating free hanging channel greater than 6". The real goal is simply trying to avoid shorting out the float...even if it is little as 1/4" you will be fine... you will also have to avoid hitting joist when driving screws into the channel, this too will short the ceiling.
Also you will need to leave 1/4" gap around perimeter of the ceiling to avoid the hard connection in the corners...fill with acoustical caulk clean and paint..no tape and mud...

Even though RC is not the same caliber as clips and channel you still want to reduce as much hard connections with in the system as you can.

Did you use real barrier(MLV) or actual black roofing paper or similar product?
Randy Sieg

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www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

HokieMan

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Re: RC2 installation help
« Reply #2 on: October 25, 2011, 02:38:30 AM »
So All I really need is a gap from the perpendicular wall? Its hard because the last joist ends right where the wall starts. I'll try to trim the ends so that it doesn't touch the drywall.

I didn't know you weren't supposed to mud and tape at all. Interesting. Would green glue work as an okay caulk for the 1/4inch gap?

I know I'm going to get shunned for this, but instead of going with the MLV I just doubled up on roofing felt. My pocket couldn't handle the cost of the MLV, and I read some stuff online that said roofing felt is not as good, but better than nothing.

Thanks again.

Randy S

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Re: RC2 installation help
« Reply #3 on: October 25, 2011, 04:07:17 PM »
You might have to add a 2x6 to the side of the joist to secure the channel.

Green glue is NOT acoustical caulk it will NOT work .

No mud and Tape...clean and paint...

No shunning here :) ....it is better than nothing...but drywall is better than that product.
Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

Randy S

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Re: RC2 installation help
« Reply #4 on: October 28, 2011, 05:17:07 PM »
I just wanted to make sure I was crystal clear on this point...

You will tape and mud the field only.....finish field as desired.

The perimeter only will have the gap and caulk , if you dont like the look you can hide the gap with molding attached to the wall only 1/8" gap at top fill gap with caulk where the ceiling meets.
Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

HokieMan

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Re: RC2 installation help
« Reply #5 on: October 28, 2011, 05:19:37 PM »
Thanks Randy.

Here are some pictures to give you an idea of what it looks like. Now that I have the felt covering my framing, it would be very hard to install extra 2x6s.





What type of acoustical caulk do you recommend?

You can also see that I have a soffit in the middle of the room. I framed it with metal studs (the rest of the framing is with wood). I figure that I don't need to add resilient channel to it because its already suspended from the ceiling.

Another problem I'm having is that the foil tape is not sticking to the felt.

I'd appreciate any suggestions.


Randy S

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Re: RC2 installation help
« Reply #7 on: October 28, 2011, 05:30:07 PM »
Ok lets get on the phone....

call me toll free 1-888-942-7723


Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

HokieMan

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Re: RC2 installation help
« Reply #8 on: October 28, 2011, 06:34:46 PM »
For all those out there reading this thread - If you need help, call Randy. This guy knows his stuff! He just dropped buckets of knowledge on me.