neoprene between wall and floor/ wall and ceiling?

Freddy G · Post by **Freddy G** » Sat Feb 07, 2004 11:09 am

Hi,
OK, I think I've got the idea of how to do a double wall but my question is, does the wall itself rest on a neoprene strip (it's a concrete floor) and if so, do you fasten the wall to the concrete right thru the neoprene? Like with tapcon screws? Same for the wall to ceiling....neoprene stripbetween ceiling and wall? And fastened thru the rubber right to the ceiling?
Cheers,
FreddyG

knightfly · Post by **knightfly** » Sat Feb 07, 2004 2:48 pm

First, do you mean a true double framed wall, or just doubled wallboard on each side of a single frame, or something else?

Generally, unless your floor is uneven you wouldn't put anything under your floor plate in a wall. Sealing takes place when you start to apply the wallboard..

You didn't mention several other things, like whether you're talking about steel stud construction or wood, what this wall's main purpose is, whether it has to be load bearing, etc -

If you can be more specific, so can we... Steve

Freddy G · Post by **Freddy G** » Sat Feb 07, 2004 11:14 pm

Hey Knightfly,
Thanks for the quick reply.
Yes, I mean a true double framed wall between the control room and the live room.
It will not be load bearing.
It will have steel studs.
So I put the floor plate directly on the concrete?
How about the wall plate on the ceiling? If I attach it directly ,
isn't that coupling?
Thanks....

knightfly · Post by **knightfly** » Sun Feb 08, 2004 10:09 am

Right - the floor plate directly on the concrete (if the concrete is wavy, you can put construction adhesive down to even it. If it's REALLY wavy, I'd level it with concrete Fix-all or similar.

Here is an example of wall sway control without hard contact -

http://www.johnlsayers.com/phpBB2/viewt ... 8&start=45

the air gap at the top would depend on your spans, so I'd need to know your ceiling joist span to answer that part - if your joists were set up for a deflection factor of L/360 (trypical) then the length of your total joist span (in inches) divided by 360 is the total deflection under normal loading that would be expected.

Example - your span is 16 feet - 16 x 12 = 192 inches, divided by 360 = 0.533 inches. So if you allow a vertical air gap at the top of the wall (not counting the neoprene) of 9/16" (0.5625") that would be enough so that the joist deflection doesn't allow contact with the vertical wall.

That whole thread has good info on walls, BTW... Steve

Freddy G · Post by **Freddy G** » Tue Feb 10, 2004 12:54 pm

Hi Knightfly,
Here's a drawing of the proposed double wall between control room and live room. What do you think?

http://home.cogeco.ca/~chuckie1/mp3s.htm

knightfly · Post by **knightfly** » Tue Feb 10, 2004 5:14 pm

Is there concrete poured over the top of the corrugated steel, or is this a roof? Do you intend to put anything UNDER the corrugated, or is that to be the final ceiling? Do you need serious isolation upward?

Keep in mind that no one component of a building or room can be decided without knowing what else it has to interact with - so if you can describe more of your construction, surroundings, isolation needs, etc, I can probably come a lot closer to helping you figure out what to do... Steve

Freddy G · Post by **Freddy G** » Wed Feb 11, 2004 1:19 am

Hi Steve,
Yes, concrete is poured over the steel ceiling.
Nothing will be under the ceiling in the live room, making it 10'8" high.
I do not need isolation upwards.
Basically what I have is a large open room 36' X 18' that I want to cut in half with a double wall. to make one side a live room and one side the control room.
All of the perimeter walls are stud and drywall and I'm not too
worried about isolation outwards...only between control and live room.
There are some steel trusses hanging down from the ceiling that would make it difficult to make the control room walls extend to the full hieght of the ceiling, so what do you think about hanging an acoustic tile ceiling at about 9' for just the control room? (just below all the trusses)

knightfly · Post by **knightfly** » Fri Feb 13, 2004 5:10 pm

Freddy, sorry I almost let this fall through the cracks -

First, do NOT cut your room exactly in half - square rooms SUCK for acoustics. You need to make one room or the other larger, and that would depend on your use. Large control rooms are good if you do a lot of synth work in the CR and have several guests at a time, or do quite a bit of DI recording with players in the CR instead of in the tracking room. On the other hand, large tracking rooms have better acoustics, and are easier to squeeze a 36 piece orchestra into...

A drop ceiling in your case would work well. Just put about 12" of fiberglas batt insulation over the tops of the ceiling tiles and keep the floor live, and you're better than halfway there on your acoustic treatment.

For your wall between CR and live room, I'd go with a steel stud version of the 63 dB example here -

no Resilient Channel needed, and you can add a third layer of wallboard to either or both sides for even more isolation. Keep in mind, though, that 63 dB can't be maintained with less than two $5k professional studio doors in tandem, so the extra wallboard layers would probably be pointless... Steve

knightfly · Post by **knightfly** » Fri Feb 13, 2004 5:12 pm

If you post your total ceiling height, I can give you some possible combinations of dimensions that will work better acoustically than two square rooms... Steve

Freddy G · Post by **Freddy G** » Tue Feb 17, 2004 10:18 am

thanks Steve,
The total ceiling hieght is 10' 8", that is with the ceiling tiles removed. With the ceiling tiles installed it is 8'. I was thinking about removing them for the live room and having the full 10'8" in there (although you can see all the ceiling guts that way...hvac, lighting, joists and beams, etc.)
I also think that maybe I would like to have a finished ceiling in the control room so it looks cleaner. It would be a drop ceiling (acoustic tiles? drywall?) at a hieght of 8'.
Regarding the $5k professional studio doors in tandem, ouch! Do you have any next best thing suggestions as far as a door?
Thanks again,
Freddy

knightfly · Post by **knightfly** » Wed Feb 18, 2004 3:59 pm

Depending on just how much isolation you need, you can look for a pair of exterior, solid core (not carved or paneled) pre-hung doors WITHOUT any holes cut for door knobs/latches - the minute you cut a hole thru the door for a knob, you lose probably around 10 dB of isolation - even if you caulk around things and try to seal it afterward, the metal penetration is the main problem.

You would mount these doors back to back, so that they swing away from each other - once they are mounted in the frame and shimmed true, you stuff the cracks full of insulation with a small rod or screwdriver, then caulk both sides thoroughly.

If you put some soft foam weatherstrip carefully around the door opening and get a pair of commercial door closers that are adjustable, you can get a pretty good seal just with the tension from the door closer. For handles, you would use surface mounted plates with pull handles, and short enough screws that they don't penetrate through the door. For the inside of each door (they would be back to back, one in each wall frame) you can screw one of those large stainless plates (sold for that purpose) to each door for a push shield.

For the bottom seals, you can buy drop seal kits - I don't have much info on that yet, here's one place that will sell the seal kits for a few hundred $ -

http://www.acousticalsolutions.com/prod ... l_kits.asp

In some cases, you can save $$$ by building your own doors from scratch - I wouldn't recommend this to anyone who doesn't have a full-fledged wood working shop however.

If you're willing to step over a higher than usual threshold you can save the cost of the drop threshold by rabbeting the bottom of the door, placing a solid board across the floor between door frame stiles, and filling the rabbets with rubber surgical tubing wrapped in cloth and stapled in place, similar to automotive weather stripping. If that makes no sense to you, say so and I'll do a sketch or two. The downside of this method is that for moving equipment through the door you'd need some kind of temporary board or ramp to keep from messing up your door seals.

If you can draw a sketch of your proposed wall/door layout, it would be easier to discuss... Steve