[ScottF]

Hello all,


Room info:

Basement HT, 18' x 16' with 8' 9" from slab to I-beam joists. The above family room is all hardwood floors.


I'm having a hard time finding RC2 resilient channel locally. Would hanging drywall from 2x2 furring perpendicular to the joists give me about the same result as RC2?


Or,


Since I have 8' 9" to play with, would you recommend a drop ceiling instead? I do need to build a soffet outta MDF to hide an HVAC duct. I may run the soffet all the way around the ceiling for aesthetics.


Also, two walls are poured concrete. I plan on 2x4 framing an inch or so away from the wall with R11 batt insulation. Should I also put up 4 mill poly between the batt and drywall for vapor barrier or is the batt enough? I'm in NE Atlanta.


Thanks,

Scott

 

[dwightrahl]

Scott,


I haven't used the RC myself, but from what I've learned about it, I should think that you'll get a similar result by using furring strips.


I think that running the soffit all the way around the perimeter of the room would give you a very nice looking ceiling effect - especially if you introduce some square columns around the room. The columns offer a good location to place wall sconces (this is what I did in my theater, so I'm a bit biased toward this look...). MDF is pretty heavy, and produces a very fine dust when cutting. I chose to make my soffits out of metal 2x2's and drywall, with fiberglass insulation inside to help avoid sound problems.


Given the choice, I'd go with a drywall ceiling rather than a suspended ceiling. I have to use a suspended ceiling in my theater due to pipe/duct/wiring access constraints; if that wasn't the case, I'd go with drywall for a couple of reasons:


1) I prefer the look of a drywall ceiling over a drop ceiling.

2) A properly installed, double-layer drywall ceiling offers better "soundproofing" than a drop ceiling does (in general).


Good luck and let us know how you make out.


Dwight

 

[ScottF]

Thanks Dwight!


I prefer the look of a drywall ceiling too. I'll double up the drywall and stager the seams. I'll wait and see if anyone else chimes in about 2x2 furring instead of RC.


Scott

 

[billwil]

While this option would cost slightly more because of the required joists, you could consider floating a ceiling. Depending on how the two existing walls are built, this may give you the most isolation, and would only cost you about an inch of ceiling height.


You can do this by hanging new joists on your walls (depending on the joists, you may be able to get away with 24" OC spacing since they do not support any weight above...but check with building codes, ratings of joist, etc.). These new joist would fit up parallel to and next to (up inside of) your existing floor joists, but not touch existing structure. They would drop down an inch or so below where the current joists come, and you can attach your dobule drywall directly to the new joists.


TJI (manufactured) joists are nice to use for this for several reasons. First, they are very straight (much nicer than dimensional lumber). Second, they are generally smaller than dimensional lumber for the same load (i.e. you may be able to fit existing wiring, hvac, etc. above the new joists). Also, if need be, it is safer to cut through the center for running conduit, etc. (again, check specs and code to see what safe limits are).


You can special order TJI type joists even from places like Home Depot (pro desk) from about $1.30 per foot on up (depeding on size and rating needed). This stuff works well for building larger risers and stages as well. Just caulk the heck out of it to make sure nothing rattles.


Hope this helps. Let us know what you end up doing and how it works out.

 

[jf1]

Quote:

Originally posted by billwil While this option would cost slightly more because of the required joists, you could consider floating a ceiling. Depending on how the two existing walls are built, this may give you the most isolation, and would only cost you about an inch of ceiling height. You can do this by hanging new joists on your walls (depending on the joists, you may be able to get away with 24" OC spacing since they do not support any weight above...but check with building codes, ratings of joist, etc.). These new joist would fit up parallel to and next to (up inside of) your existing floor joists, but not touch existing structure. They would drop down an inch or so below where the current joists come, and you can attach your dobule drywall directly to the new joists. TJI (manufactured) joists are nice to use for this for several reasons. First, they are very straight (much nicer than dimensional lumber). Second, they are generally smaller than dimensional lumber for the same load (i.e. you may be able to fit existing wiring, hvac, etc. above the new joists). Also, if need be, it is safer to cut through the center for running conduit, etc. (again, check specs and code to see what safe limits are). You can special order TJI type joists even from places like Home Depot (pro desk) from about $1.30 per foot on up (depeding on size and rating needed). This stuff works well for building larger risers and stages as well. Just caulk the heck out of it to make sure nothing rattles. Hope this helps. Let us know what you end up doing and how it works out.

From what and how do you "hang" the new joists?

 

[billwil]

Quote:

Originally posted by jf1 From what and how do you "hang" the new joists?

...from the wall frames using joist hangers (brackets). There are many here who have done this, so they may be able to give more experience-based feedback; I simply have this in my plans to use this method in my "room inside a room" construction plan. I will start in a month or so, so my input is theoretical thus far. Hope this helps.

 

[Dennis Erskine]

You can use RSIC-1 isolation clips and HAT Firring Channel (from Home Depot). www.pac-intl.com

 

[ScottF]

Thanks Dennis!


You should've seen the looks from the Home Depot guys when I asked for Resilient Channel... one guy said, "what? Brazil Channel!?!?!?!" Maybe they'll understand "Hat Channel".


Scott

 

[GRBoomer]

Any ideas on how to hang a CRT projector using RSIC clips?


I was thinking I would still have to run two or three LVL joists to support the load of the projector.

 

[jf1]

Quote:

Originally posted by ScottF Thanks Dennis! You should've seen the looks from the Home Depot guys when I asked for Resilient Channel... one guy said, "what? Brazil Channel!?!?!?!" Maybe they'll understand "Hat Channel". Scott

Me too! I still have yet to find Resilient Channel in my area, I have found glazed staring and lots of mumbling though.


Thanks Dennis for the reply.


JF

 

[ELB_III]

For what it's worth, I mounted furring strips perpendicular to my joists and then put RC along the strips. It's probably not the perfect acoustic application (I'll defer to the experts here) but I can tell you that I can crank the HT pretty loud with very little sound going through the ceiling to the first floor above. Of course I have no idea what the impact is without all that stuff but I'm satisfied with what I've got for the first time (building a HT, that is).


I got my RC locally from a company called General Building Supply aka Strober up here in the northeast. But I went through the same thing with asking the folks at the home centers about RC. They were all like "Huh?".


As for mounting my projector, before hanging the drywall ceiling, I installed two pieces of 2x4 across one of the joist cavities so they were flush with the joists themselves yet perpendicular and marked the locations. The 2x4's were spaced to accommodate the projector mount I purchased. Once the ceiling was up, I went back the the location and installed the mount with the hardware going through the drywall and directly into the 2x4's.


The key here is to be sure you mount the 2x4's in the proper location according to your screen and work the furring strips around the area.


Good luck.


Cheers!


- Ed.

 

[Dennis Erskine]

Three LVL's to support a projector? That projector must weight as much as a large SUV or small house.


I had a 220+lb worker do chin ups using the HAT channel in the RSIC clips. They'll hold a projector fine.


The HAT Firring channel is available from Home Depot...although most home depot folk don't know it. The need to look up HAT FIRRING channel on their stocking system to find it.

 

[emillika]

I noticed in the RISC-1 box that PAC calls for Hemmed edges on the 25 guage hat channel... I couldn't find better than 25 guage at HD, Lowes or Menards here locally and all the hat channel the big three carried is unhemmed. Should I worry or continue on with the 25 guage unhemmed variant?


Thanks.


Elmer

 

[ScottF]

OK...


So, Hat Channel is going to be a "special order" at Lowe's (so the guy tells me). That means there's a minimum too! And, probably way more than I need... ugh. Looks like I'll be going back to Resilient Channel, which is also proving to be rather elusive...


The search continues!

 

[Dennis Erskine]

Home Depot has the HAT Firring Channel and it works fine with the RSIC-1 clips. Again, however, they'll say they don't have it, don't know what it is, etc. Have them look it up in their system as HAT Firring channel. If that fails, email me and I'll get you their SKU number.


Scott...I don't know about the Home Depot in Duluth; but the HD on Paces Ferry has it in stock.

 

[GRBoomer]

No, my projector is a Barco BG808s. Only 150lbs. My wife's view of it though, is 150 tons. Convincing her to have it on the ceiling is the tough part.


Thanks for the reply Dennis.


I was able to get Menards to find RC-1 (resilient channel) in their computer system by having them search ALL the products supplied by their supplier of metal studs. They were able to find RC-1 when I could guide their computer search.

 

[curtisG]

Quote:

Originally posted by Dennis Erskine Three LVL's to support a projector? That projector must weight as much as a large SUV or small house. I had a 220+lb worker do chin ups using the HAT channel in the RSIC clips. They'll hold a projector fine.

Dennis:


The RSIC-1 installation notes state that the dead or shear load on the clip should not exceed 36lbs to make sure that the acoustic performance isn't compromised.


Between the weight of the dual layers of drywall + projector on a 2' x 4' RSIC grid, wouldn't this be a problem?


--curtis

 

[GRBoomer]

The other thing I worry about with the RSIC-1 is that it will not isolate the projector from the floor flexing above. My 3 year old likes to dance/jump in the family room, above the planned theater. When she dances I can feel the floor move. I may sister the joists to firm up the floor, but I don't want to get motion sickness watching a large screen image bouncing around.


The Kinetics hanger looks like it may do a better job of isolating the mechanical (real low frequency

Both systems, kind of hide that fact, that their STC ratings are based on a floor with a layer of concrete/gypsum above the floor decking. So unless you put the concrete in, an STC of 60+ will not be achieved. I wish they would supply some controls as a reference. There are other places that list the STC of a ceiling assembly, but every test is different. It would be better to see the improvement that their systems have on acoustical isolation, versus just absolute STC ratings.


Any thoughts?

 

[ScottF]

Quote:

Originally posted by GRBoomer The Kinetics hanger looks like it may do a better job of isolating the mechanical (real low frequency

Wonder what those cost? Looking at RSIC-1 clips, I'll need 80 at about $5.00 a pop plus the hat channel. This is getting expensive quick!


Since I have 8' 9" to the joists, I may go for a floating ceiling instead. I just need to find out what size 2x at 16' long I need. 2x10 I suspect would be sufficient.

 

[Dennis Erskine]

With a wood floor (oak over wood subfloor), RSIC-1 and one 5/8" sheet of drywall, STC57, with two layers of 5/8", STC 61.


If you have children jumping on the floor above, neither the RSIC-1 nor the Kinetics spring clip will prevent motion of the projector.