Hello Michael, say, I hate to answer for him cause HE may have already done that, but there are some observations I've made. First, to my way of thinking, 1" sounds like a disaster waiting to happen. I poured a 1" veneer on my cracked patio once. ARRGGGRRRRRRR!! Ha! Lasted a month befor it started cracking too!. There is not enough concrete around the aggregate to give any strength. There IS no strength there, especially with the "poly" below. Second, the only room that has interior room in a room walls is your control room. And every "floating floor" I've actually seen, is really part of a "floating room". (ie, the walls are on the flooating floor)
Imagine, IF your walls of the control room are fastened to the same slab as the tracking room, right there you have negated any gain you've made with a floating floor by structural transmission through the tracking room floor to the walls of the control room. UNLESS you float the walls on rubber too! But that is the same thing as a floating ROOM! And IF your going that far, you might as well pour a 4" concrete floating
floor. But this also would require special spring isolaters mounted in the floating floor formwork, which is really a pain in the ass and EXPENSIVE. However, I HAVE built a floating floor from wood on neoprene, just never finished the rest of the room. I don't think you want to go to this extent, as it looks like your building is isolated from adjacent structures and you are not floating the tracking room anyway.
Now maybe he is talking about something else. I don't get it. Unless he is saying to do that in the tracking room
Still, 1"
I think that needs further explaination.
I am certainly no expert at this but I still have common sense, I think
Now, I have seen a couple of other ways to do this, but your so close to pouring, and the forms are already in place. But I'll add this. SINCE, your exterior wall, IS the wall of the tracking room, and your perimeter footing compleatly surrounds your control room, you COULD actually build a form for a footing/slab that is physically seperated from the building slab, for the control room. In other words, the control room would actually become a seperate building from the exterior shell. Of course, this would require rebuilding the forms adjacent to the control room so there is no building slab in the control room area. Then pour the exterior shell slab and footing first, let it cure, then remove the forms, and reform for the control room slab and footings. There would be a gap in between adjacent exterior footing and interior(control room)
footings but personally, I would just lay a strip of "poly" as a 1"filler between the two footings/slabs BEFORE I poured the CONTROL ROOM slab/footing(with cable chases). Of course, the control room has angled walls, which makes for part of the exterior shell footing actually becoming a slab to the point it meets the control room footing. I would also, frame for a footing at the tracking room wall that seperates it from the CR. Same with the vocal booth and SEE ATTACHED DRAWING. This way your whole control room is isolated from the rest of the structure. But alas, this requires more time and money. Its just the way I would do it. I see no need to isolate the tracking room from the exterior shell, as you have brick exterior walls and staggered stud walls on the inside of that too! This would be gross overkill, and lets face it. That would be the way they do it to isolate from a TRAIN yard next to the studio and you DON"T need it!! Or do you?
Now this brings up one more thing. You showed the roof truss's your using, and I assume that they are perpendicular to the length of the room, is that correct? Are you building a seperate interior ceiling over the control room structuraly supported by the control room walls?(I assume you are). If so, you have 5/6ths of a floating room right there! Forming for a seperate control room floor would complete it. AGAIN, I am no expert, but I have seen pictures of doing it this way. Saves pouring another slab on top of the building slab. I really don't know if they consider this a "floating floor" or not, but it is structurally disconnected from the main slab. However, you are the only one who knows if you want, or need this much iso. Hell, if your recording acoustic instruments only, what the shit! Go with what you are doing! Then again, maybe you are using RC on the ceilings. Thats what I mean about not seeing all your construction details. Only plan.
One other way I see. Build a control room wood floating floor, with the walls built right on top of it. My floor was built in sections. So I could attach 1/2" ply to the bottom face before I laid each section in place.(5' x 12' as I had that size mdf available to me for the floor panels) I simply contact cemented 3/4" x 2"w x 4"L (4" x 4" at the wall perimeter) neoprene strips @12" o.c. to the 1/2" ply bottom at the complete section perimeter and in line with the joists(1 1/2" x 3 1/2" kiln dried poplar is what I used.) Once each section was in place, I bolted them togeather. Of course, there were cable chases framed in also between two sections. Once the whole floor was in place, I laid a
vapor barrior in the bottom. I then FILLED THE VOIDS between joists with KILN DRIED SAND. Then another vapor barrier over the whole thing. Then I screwed the 3/4" MDF top panels in place. Perfect subfloor for 3/4" x 6" T&G oak finish flooring(I had thes custom milled at work). There were removable MDF cable chase panels also(thats the
reason for 6" wide oak so the seams at the cable chases matched the flooring. Worked great! One other thing. I use square head recess screws on EVERYTHING. They really work fantastic. I buy them in bulk, different lengths. Even on wall studs to plates. Try em, you'll like em! They don't strip like phillips!
Well shit Michael, I've used up my whole morning writing this and I hope it helps. Sorry for the ebosity. Ah, what was it I was going to ask? Oh well, another reply later today when I remember. DUH!! Later.
fitz
