Author Topic: RC-2 or RC-8 in ceiling for basement  (Read 21460 times)

DAWGFAN

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RC-2 or RC-8 in ceiling for basement
« on: September 09, 2006, 02:49:22 PM »
Does anyone have experience with RC-8?  I am finishing my basement ceiling and trying to determine whether to use RC-2 (as recommended by super soundproofing) or RC-8 (as sold by Auralex).  I appreciate your comments.

John

johnbergstromslc

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Re: RC-2 or RC-8 in ceiling for basement
« Reply #1 on: September 11, 2006, 05:19:23 PM »
If you're serious, start with the SSP clips, then use RC-1 or RC-2 'hat' channel before installing drywall.  

You'll get much better performance with the addition of the SSP clips.

DAWGFAN

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Re: RC-2 or RC-8 in ceiling for basement
« Reply #2 on: September 12, 2006, 02:01:32 AM »
Thank very much for the recommendation.  The SSP clips sound very advantageous.  The SSP clips from soundproofing.org appear to only work with DWFC, which looks like a HAT Channel.  

Soundproofing.com states in their article, however, that resiliant channels are more effective than HAT channel.  

Would you expect the same performance from the RC-2 'hat' channel and SSP clips  as to the performance of similar clips with RC-1?

This project is an attempt to simply block moderate noise between a basement and a main floor (and vice versa).  The basement will not have a theatre, but will have a larger entertainment system.  I'm planning on only doing the ceilings...the walls are concrete, with the other side being outside (or under ground).

Thanks again, in advance.

John


johnbergstromslc

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Re: RC-2 or RC-8 in ceiling for basement
« Reply #3 on: September 12, 2006, 11:14:26 PM »
As sold on soundproofing.org, RC-1 are 'hat' channels, 1" depth.  RC-2 channels are deeper, something like 2 1/4" - you can check on their site.  RC-2's simply lower your ceiling more, allowing you to get more insulation in the joist cavities.

If you're going to use the SSP clips, don't worry about differences in performance.  It is an excellent system and, as you said, you only need moderate soundproofing (not a recording studio, etc.) any differences will be minor and unnoticeable, if you plan on using 2 layers of drywall on the ceiling (recommended).  

Just remember to keep your field joints tight (but seal them beforehand) and leave 1/8" - 1/4" at the edges and do some good sealing there before you mud and tape.  Also, it might be a good idea to use an 'old work' electrical box for the light(s) instead of a conventional one, rigidly attached to the joists.  It's more work trying to get the thing centered, but it can otherwise transfer a lot of sound energy.  Also, seal up the holes in the box and the gap around it too.  

If you've done the ceiling and find that the walls are transferring a lot of noise, you can tear off the drywall and use the same system (SSP clips + hat channels + double drywall) there too.  I think you'll get an STC (roughly) of 64, which is excellent.  It'll be a quiet place.

Keep your quality control high and I think you'll be pleased with the results.


hickory_stick

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Re: RC-2 or RC-8 in ceiling for basement
« Reply #4 on: September 15, 2006, 12:27:18 AM »
Not quite right, John.  RC-1 channel is "Resilient Channel" (one leg "Z" channell with holes in the web designed to limit sound through the strip.

RC-2 is simply 2 legged channel.  Both are about 7/8th inch high.

RC-1 is for walls (one leg), RC-2 is for ceilings (2 legs).  RC_1 can be used for ceilings, just takes twice as many.

Now "Hat" Channel is "Furring Strip" In the trade.  This profile _/-\_ gives it the name.  It is ideal to fit the sound control clips many sell for wall sound isolation.  It is over an inch in height, depending on the source.

An excellent explanation of all this is at
http://www.soundproofing.org/infopages/channel.htm

Hick

DAWGFAN

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Re: RC-2 or RC-8 in ceiling for basement
« Reply #5 on: September 16, 2006, 02:28:15 PM »
I guess this is the source of my confusion.

First) Does the RC-2 have two legs, one on each side?  To me this would resemble a HAT channel.  Or are the two legs on one side, leaving the other side slightly off the joist?

Second) Would the SSP clips work with RC-2?  Are there similar clips available that would work with RC-2 if the SSP clips we've discussed won't work?

Thanks again to you guys for helping me out.  I'd like to order this stuff up fairly soon, but want to nail down the advantages and the availability of components.

John

johnbergstromslc

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Re: RC-2 or RC-8 in ceiling for basement
« Reply #6 on: September 17, 2006, 12:19:44 AM »
Well, the RC-1 picture on the supersoundproofing order page sure looked like hat channel to me - maybe this is something that needs fixing.

It's possible, but definitely do not use the one-leggged channel on ceilings - it will be a frustrating, time-consuming debacle, full of costly mistakes.  Been there.

Tell you what, get the SSP clips from supersoundproofing and get the hat channel locally (Home Depot/Lowes.)  Then you won't have to pay to ship a large item (that gets damaged easily) and you can take a clip with you and test fit it on the channel.

If it fits, use it, and don't worry about what designation it is.  They just call it DWFC (Drywall Furring Channel) anyway - it's just a standard piece of rolled, galvanizeed steel.  No need to pay 'boutique' prices and ship something across the country that you can get down the street...

I think you have some confusion as to how to install it.  The clips are installed parallel with the joists and the channel is inserted in the clips, perpendicular to the joists.  If you weren't using clips, the channel would still be installed at right angles to the joists.

P.S. The 'SSP' clips are also known as 'Isomax' clips, but there's no difference in price.  However, the maker of Isomax clips have an excellent website, with sound test data, specs and all details of installation.  Check it out at:

http://www.kineticsnoise.com/arch/isomax/index.html


supersoundproofing

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Re: RC-2 or RC-8 in ceiling for basement
« Reply #7 on: September 18, 2006, 06:51:34 PM »
quote]Tell you what, get the SSP clips from supersoundproofing and get the hat channel locally (Home Depot/Lowes.)  Then you won't have to pay to ship a large item (that gets damaged easily) and you can take a clip with you and test fit it on the channel.

If it fits, use it, and don't worry about what designation it is.  They just call it DWFC (Drywall Furring Channel) anyway - it's just a standard piece of rolled, galvanizeed steel.  No need to pay 'boutique' prices and ship something across the country that you can get down the street...


[/quote]
We make these channels available to the customer because they are usually not available from  common hardware stores like Lowes or Home Depot, only from builders supply, who usually do not like working with DYI-er's.

Additionally, it's easy to get the wrong thing which WILL NOT FIT, causing problems to be ready to go, then have to go find the right thing.  (Or worse, have the ignorant contractor use it).

SIngle legged and double legged furring channel comes in a variety of shapes and sizes, as well as thicknesses.  For instance the metal can be in 18 or 20 gauge- the thicker passing sound more readily.

Many people get confused and use 2 legged furring strip as RC-2  and/or "Z" channel as RC-1.  (Sometimes having been told by the ignorant supplier: AHhh- it's all the same".

It's not- RC channel has holes in the webbing.


BJ Nash

johnbergstromslc

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Re: RC-2 or RC-8 in ceiling for basement
« Reply #8 on: September 18, 2006, 10:04:38 PM »
Not hard to figure out the math on this one.

DWFC from:

Supersoundproofing - $4.00 for a 5 foot length (plus shipping).

Home Depot - $2.43 for a 10 foot length, no shipping costs.

 

hickory_stick

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Re: RC-2 or RC-8 in ceiling for basement
« Reply #9 on: September 19, 2006, 01:41:33 AM »
Are you sure?  I have never found a Home Depot with the right furring "Hat Channel".  They have it sometimes but not the right stuff.

Hick

DAWGFAN

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Re: RC-2 or RC-8 in ceiling for basement
« Reply #10 on: September 19, 2006, 02:08:38 AM »
I haven't seen furring strips, resilient channels, or HAT channels at either of our local Home Depot or Lowes stores....but then again, I haven't asked to see if I can order it.   I'll drop by tomorrow and see what they can do for me.  Once I can get hold of a channel, I'll determine what 'clip' would be best for that make of channel.

Thanks again for all your support and interest in my project.

johnbergstromslc

  • Guest
Re: RC-2 or RC-8 in ceiling for basement
« Reply #11 on: September 19, 2006, 06:19:27 PM »
Check in the drywall department.  It's usually in the same area with the corner bead, steel studs, etc.

If not, look in the phone book for 'drywall supplies' or 'drywall contractors' and they can hook you up.


DAWGFAN

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Re: RC-2 or RC-8 in ceiling for basement
« Reply #12 on: October 06, 2006, 10:59:26 PM »
All,

Found RC-2 at a drywall shop down the street for $5.26/12 feet.  They also sold 7/8 DWC, 25 guage for $4.96/12 feet.  I think if the isolation clips are around $5.00/clip, my cost will increase 5 fold ($5.26 vs. $25.00 per 12 foot section).

Not sure I want to spend that on a basement....maybe if I were building a home theatre.

I think I'll go with RC-2, maybe use the absorbent tape between the drywall and channel AND channel and stud.  Should get decent results.

I appreciate everyone's interest and constructive comments over the last few weeks.  They have been very helpful.

John