RC?

Started by cfuehrer on 5 August 2003. 20 replies. In the Library under Walls, floors and ceilings.

Originally posted at johnlsayers.com, topic 530.

What is the recommended RC I should be looking for? What is a typical price for it in the states?
My Local supplier charges 1.43 for a 12' long pc of RC Bryan Giles
But what is the name and/or brand I should ask for? Don't want to get the wrong thing.
The USG part is RC-1, usually available at drywall/insulation contractors. It's a "single legged" type - if you use so-called "hat" channel, it requires separate isolator clips for mounting. the clips are about $5 each, and you need one every 4 feet except for perimiters of panels, where they need to be one per stud. Check out this thread for more info on wall construction, including how to mount RC and where to use it - http://johnlsayers.com/phpBB2/viewtopic.php?t=529 Keep calling until you find someone who handles the RC-1, sometimes it's hard to find... Steve
I just called my local supplier Livonia Building Materials and asked for Resilient Channel. They knew what it was and had the order ready for me. I don't think it is that deep. Just find a REAL building supplier. These guys know what this stuff is. Bryan
Bryan, specifically WHAT brand/part number are they selling, what exactly does it look like, and what's the price? Thanks... Steve
I have no Idea what brand. It looks like what I have seen online similar to Auralex's RC-8 Bryan Giles
Thanks Bryan, found their page and more info on hat channel as well... Steve
Sorry Carl, I shoulda posted that. I did notice that the philips stuff doesn't have the same long slots in it that make the RC-1 more flexible - they want you to contact them for specs, I didn't do that yet. If you can find an Auralex dealer close, their RC-8 is nearly identical in every way to the original RC-1 by USG - this is the stuff that 99.9% of all tested wall designs that have RC in them were tested with. The auralex guy today said most of their dealers charge around $130 for a box of 24, 8 foot pieces - works out to about $.67 per foot. I know this sounds steep, but this is a niche market. Basic economics apply here. If you want a better wall by about 8 dB, for higher cost you could use the RSIC-1 isolators in combination with "hat" track - the clips cost around $5 each, need to be on 48" centers or tighter, and that's not including the cost of the track. Not sure yet what that runs. Should run altogether around 3 times what the RC-8 would cost, but 8 dB is quite an improvement if it's worth it to you. Here's their site http://www.pac-intl.com/rc_update_12-02.html If you scroll down near the bottom of that page, you'll find a comparison chart between the newer RC and the RSIC clip system - I'm pretty sure, though, that they're comparing to the LESS effective, newer version of RC by that company - read the article, and the chart doesn't say WHICH RC they compared to. It also doesn't say what kind and how many layers of wallboard, or anything else that would give it an air of respectability. Personally, if given the choice at this moment in time I'd go with the Auralex. I think the REAL performance improvement of RSIC's might be as little as 3-4 dB over the Auralex, and here's the cost comparison: RC-8, $.67/foot, 7 rows (16" apart), 10 x 12 x 8 foot room (just for comparison, no I would NOT purposely build this) 44 feet per row, 7 rows, 308 feet, figure 320 feet - $214.40 and you're ready for wallboard. RSIC-1 - same room, walls only, 24" centers both ways, 48" except at periphery, takes about 84 RSIC's at $5 a pop, for $420 - now you need 5 rows of hat channel 44 feet long, or 220 feet - haven't priced this yet, but probably around $.60 per foot or another $132, for a total of $552 before you can add wallboard. To contrast this, it would take 11-12 sheets of drywall for an entire extra layer, at $5.50 per sheet or $66 - (sorry, British members, I'm really NOT trying to make you feel bad - :( :( ) OK, this is all hypothetical in that I didn't figure ceiling, fasteners, paint, etc, but you would need all those in either case. It still looks like over $300 more for using the RSIC clip setup on the walls of our 10 x 12 x 8 room. It's been postulated that most of the added STC from RSIC clips is just because of the extra air space depth - the hat channel is 7/8", the RSIC's stand off about 1/2" more, so you gain almost an inch of air space over RC. I'd probably frame with 2x6's for an additional 2" of air instead, at a cost of about $30 before I'd go for the RSIC's - Just my own feeling on this. OK, 'nuff ranting for now... Steve
Hmm, They must've improved the product a little, those holes you see is a repeating pattern about 1" from each other for the total length of the channel. Hope I was clear with that. Bryan Dunno is that helps or hurts. Just called them and asked to send me over a spec sheet
Bryan, if you're talking about the holes in the "stand-off" portion of the channel, those are the ones that were long slots in the original RC. I've attached a pic (from the Pac-intl site) that shows the diff between the newer, untested, stiffer version and the original... Steve
Image not preserved: rc_update2.jpg
So what makes it better the fact that it lifts the dwall off the wood stud or the construction of the channel. Doy you want a stiffer channel? The one I bought seems pretty stiff however, I have no reference. Bryan
Actually, you want the section of the channel that causes the "lift" to be as flexible as possible, while still being strong enough to support the drywall. That's why the newer stuff (lower in the photo) probably doesn't work as well. Note the long slots in the "riser" portion of the original RC-1 channel - they are 3" slots every 4", so you only have 25% of that 25 gauge "riser" that's connected. The auralex RC-8 is virtually identical to that first design, that's why I would pay the extra for it over some other designs. It's still about 1/3 as expensive as the RSIC clips and hat channel... Steve
so does that mean what I have is junk? Bryan The picture online does no justice to what it actually looks like. The holes are like what you see, in 3 sets of 3 like that, but the sets of 3 are spaced about 1.5" apart and run the entire channel. I'd guess that that piece has a 50% contact Just a guess
Kinda depends on what the rest of your walls/doors/windows are, and how critical your isolation needs. Generally speaking, it's rare to find windows and doors that can keep up with decent walls for TL, and as near as I can find out the newer, non-auralex stuff is probably only about 2-4 dB worse (if that) than either the Auralex RC-8 or the original USG RC-1. If you're not using $5k Overly doors, I'd probably not sweat it - just do everything right and I doubt you'll even notice the difference... Steve
Ok, I won't lose sleep then. 4db will not make me lose my lunch. :) I have separated wall construction. (Room in a room) I have in times past been pleased with what I got using just studs, drywall and celotex. The RC is a new thing for me so from a apossible gain of 6 to 7db of isolation, I am satisfied. My main use is the ceiling in the live room as I descirbed before and the the walls of course. RC is only used in the live room, not the control room And if I heard yah and have read correctly, the CR wall on studs and LR wall on RC and studs is proper. (I am talking about the air space between the CR and live room) Bryan
Here's an update (sorta) - just got this link from Rod over at RO, haven't yet talked to these guys about anything but will - Their picture looks just like the original RC-1, but I think it's their stuff that's "not recommended for ceilings" - no pic of the "good stuff" to tell if the percentage of web perforation is right, anyway here 'tiz - http://www.dietrichindustries.com/bigdp ... sories.htm No estlimate of price yet either. I'll be calling them in the next day or two... Steve