"Floating Walls!?"

Hey everybody! Since I don't intend to float my basement floor in my studio build I came up with the idea of something like floating walls. If I screwed my framing onto the unfloated floor all vibrations of the walls would be coupled into the floor. What if my box (room in room - 4 walls and a ceiling) would only sit on my floor with some kind of damping material between the floor and the framing. Does some of you know if there is any reason why this should not work (safety, sound leakage through that damping material, ...) what leads me to my next question: what could that damping material be? If I'd use neoprene pads I could imagine that the weight of the room (roughly 5 to 6 tons for the 30m² room) will compress them so much that there would be no damping effect at all (unless I increase the thickness of the pads till soundleakage would be inevitable) Could someone help me on that one? ...or am I trying to reinvent the wheel - is there a common way of dealing with this... so far I have not seen anything like this thanks in advance

Um... it's been discussed here on the forum. Short answer... NO. Some people did do just what your saying and then... If you do some searching you'll find the threads were it was discussed and turned into not a worth while idea. Might take a bunch of searching and scanning though. There would be to much calculation involved to get the amount of neoprene correct. If your building on 1st floor on concrete slab, the earth below you is thick enough and hard to beat for isolation. (or something like that) Marc

Well i am in the same situation and i find this thread ,check it out : http://www.johnlsayers.com/phpBB2/viewt ... ated+floor Regarding this thread u and me too could get away without floating the floors which is good news . Maybe decoupling the walls from the floor with some rubber band or strong gum band / material ... I would be very interested to hear others opinion . Ciao

simply put the common and advised line in the forum here from people with vast experience in this construction - ----------------------------------------------------------------------------- Frame a wall with baseplate nailed/screwed into concrete. Insulate in between. RC1 - (this is the main part of the decoupling.) Drywall layer(s) that are off of the concrete and sealed off by a bead of caulk along with backer rod. ----------------------------------------------------------------------------- Compare the cost for thin strips of metail used in that example to the cost of neo pads where you'd have to calculate how much weight the layers and leafs (is the ceiling supported by your frame?). So the first method as GuitarDad72 highlights as well is less expensive in labor and time and is less error prone. That's where the rubber meets the road with these projects.. Rubber meets the road.. blahahahaha oooooh I kill me! <groan>.... There's even a thread here that may/maynot be a sticky - Floating floors are they right for you? Chances are NOT. It's not exactly the same thing as walls, but it's relative.

My local code requires floating walls due to expansive soils. Therefore, I have to employ something similar to the images below. The walls essentially "hang" from the top plate. Is there any way for me to still do a room within a room with independent ceiling joists? It doesn't sound like I can :( . So, am I limited to clips? And the amazing illustration from the county...

Audixium, Could you update your profile with a location. We come from all over to the forum and in order for the knowledgeable to help you, they need to know where you at. This is also going to appease my curiosity as to where in the world they build walls such as you are describing. I'd imagine some good engineering would be required to "hang" walls from a top plate. You'd have to be careful adding in the weight of 2 layers of 5/8" inch drywall for isolation purposes, not one 1/2" which is more standard construction. I'm wildly guessing but is your house/building ranch style where the long outside walls of structure take the weight of some "super truss" system which can support the weight of other walls? I'm not going to take a wild stab on how you could build a room in room but an "isolated slab" come to mind. Marc

Audixium wrote:

My local code requires floating walls due to expansive soils. Therefore, I have to employ something similar to the images below. The walls essentially "hang" from the top plate.

If you look at the clear top picture in your starting post, you see (at the bottom of the wall) a 3/4" X 3-1/2" treated ledger board that has been attached to an >existing< wall THEN the interior wall has been attached to the 3/4" X 3-1/2" treated ledger board . This is how you hang this wall to comply...in a basement I am guessing. But it does beg the question of "Why?" You are stateside yes?

guitardad72 wrote:

Audixium, Could you update your profile with a location

Sorry - swore I did that, pet peeve of mine "guessing" continents. ;) Done now.

guitardad72 wrote:

I'm wildly guessing but is your house/building ranch style where the long outside walls of structure take the weight of some "super truss" system which can support the weight of other walls?

I have two story house sitting on top of a (currently) unfinished basement. The outside walls of the basement act as the foundation walls and are concrete. The floor of the basement is concrete as well. There are two steel beams that span the width of the house with lolly columns holding them up. The first floor joists lay across the beams and concrete walls. I hang out at AVSforums.com as I'm also planning a theater as part of my basement finishing project. The pro designers over there have done a lot of installs with clips, double drywall and green glue (ceilings and all walls) in this "floating wall" fashion. It meets code approval as well. In fact, I met a neighbor of mine on AVS (no joke). He starting posting up photos and I said "I recognize that ridge." Anyway, I am watching his theater build and was able to go over and see his "floating wall" after framed up. It looks just like the first and last pics I posted - not the mini ledger board type. I was really hoping for more isolation, but don't think I'll be able to do a room within a room.

xSpace wrote:

But it does beg the question of "Why?" You are stateside yes?

Well, along the front range of the Rocky Mountains in Colorado there are veins of Bentonite. It is an expansive clay soil that in the past has wreaked havoc on properties and roads. When it absorbs moisture it can heave up to 10 feet and ruin your foundation. Our home builder dug down to bedrock, then built the soil back up using a specific engineering process. We will likely never have any problems, but the County requires specific finishing construction in basements so as not to push the entire house up if the middle of the floor heaves a few inches. This actually happened to a house my wife grew up in. Took something like $75k back in the 70s to fix the house. Anyway, I was just curious if anyone around here had dealt with a similar situation. But it sounds like I'm a little unique in that regard... :(

I was really hoping for more isolation, but don't think I'll be able to do a room within a room.

You are look at this all wrong. You are essentially developing a room within a room. Your first room wall, the concrete basement, is more dense then you would every get using a wood framed/sheetrock wall. The only real difference is that the interior wall isn't completely decoupled from the concrete due to the required use of furring strips. But it isn't like it is part of a staggered wooden frame...it's concrete!!!! Cheer up dog ;)

Yeah but... I won't be able to completely decouple the ceiling from the first floor joists. The concrete walls are around the outside of approx. 1300sq.ft. My studio portion will only take up 1/3 of that and won't completely surrounded by the concrete walls - just on two or three sides. Plus, the LFE from the theater was my primary concern. Sure with building up underneath the subfloor between the joists using drywall, green glue, and backer rod, then insulation, then clips, and two more layers of drywall and green glue (whew) I will greatly improve over standard house construction. But my biggest concern is the LFE which can flank, right? At any rate, over at AVS someone else in Colorado was considering doing a room within a room and leaving 3" of travel ABOVE the independent joists. I'm going to check into that with my county to see if it would fly. Lastly, I'm not going to attach my studs to the wall with furring strips. I'm going for as much air gap as I can stand (losing 2-4" of space). Chow.