Daiwa's 2nd floor studio build

On the previous subject of mine i had my a** saved by Ro. Thank you sir. Here we go again. Funnily enough its impossible to find directions as to what comes first and what comes after that, i guess its because everybody thinks i know it already. Well, i dont :shock: So the question is:What to do first? I have space in the office building on the second floor. What we have is concrete floor, concrete ceiling and outer walls are made of brick. So i have treated my outer walls with help from Ro and its looking good now. Plan is to build control room and recording area separated by standard double wall with double sliding doors built into it. I am not planning to build room within room or float the floor, since my isolation concerns are not that big. I am building post production studio and i will not record anything louder than human voice. I am also not too much concerned about outside noise. Of course i want best isolation i can get in these circumstances. My questions are: 1.Do i first build inner double wall on the top of concrete slab and then i build separate floor layers for each room? 2.Or do i first build floor with all floor layers like cement glaze,thin rubber,osb board and hardwood and then lay walls on top of it? If the correct answer is 1, then i have a subquestion which is: Do i screw my doublewall to the concrete slab itself or do i screw it to the cement glaze which is on top of it? If the corect answer is 2: Do i put my double wall on top of thin rubber or on top of osb board? Thank you for your help

Daiwa, Option 1! As sound will travel along flooring, I suggest that you build the walls and make independent floors inside each defined room after that, which should minimize flanking along the floor. Keep the floors isolated from the wall structure and plasterboards as well by a gap of say 6 to 10mm and fill with backing rod (Caulk saver foam) and seal with flexible sealant. WRT your subsequent question - If the Cement screed (your glaze) is already in place on the concrete, then go straight on top the screed. If you can build the wall frames direct on the concrete, then rather do that. You want the frames fastened to the concrete if possible, but not overly fastened, unless you live in earthquake country. What is the depth of the screed? I made a 60 to 70mm screed on top of concrete floor and managed to fit conduit pipes in the screed to carry all studio wiring in the floor to the desk area. This screed will become heavy and may be a structural issue on your floor! Check ! Good luck Marz

Well, thank you marz. That was fast and clear as a bell. My glaze is not on the floor yet so i will be able to fasten my doublewall directly to the concrete. Glaze will be 70mm and like you i will have many ducts for both audio and electric in the glaze itself. After that i will put some kind of rubber or polyethilene type of sheet to try to tame impact noise and osb board on top of it. Finish will be hardwood parquette floor. Only, there is a bit of an issue with me fastening wall to the concrete slab instead of cement glaze. The problem is that i have ducts going in the cement glaze from one room to another underneath this doublewall. So i will have to make incisions in the wall for ducts to get through, which makes me a bit uneasy about isolation. And if i just screw my doublewall to the cement glaze i will eliminate that problem. What to do,what to do?

Daiwa, I suggest you keep one thread going to cover your build and keep it in one place, instead of many diverse threads. Possibly rename it with an informative title: eg - Daiwa's 2nd floor 2 room studio build? 70mm of cement screed is very heavy, and may be a structural problem, so you need to review that with a structural engineer to be safe! Depending on the size of your rooms? I personally suggest you do not use a rubber mat under your floor, but fasten the OSB direct to the cement screed and the parquet flooring glued to the OSB for a solid floor. There are many discussions on this forum about not making a floating floor and it is a heavy / expensive engineering exercise to do it right and worse to do it incorrectly. Can you improve the ceiling isolation of the room below in any way - IE Add more Plasterboard below your floor or even an isolated ceiling, separate from your floor? Possibly post a plan of your rooms and your idea of ceiling structure with dimensions. Preferably with reasonable scale - I found it difficult to follow your earlier wall diagram. The ideal is for it to be completely isolated from your outer shell and fastened on top of the new inner walls. Again it needs to be engineered for the dimensions of your rooms. Wider rooms equals deeper ceiling beams. I used heavy Steel Angle bar profile for a 3.6m span and carrying 2 layers of 12mm Plasterboard. cheers!

Cement glaze shouldnt be a problem. Standard stuff is from 50 to 70 mm. I can choose in between these two. Its a new building with 8 floors and every office space has the same cement glaze. Its just the way we build overhere. I still have question in my second post which i need to have answered, so please take a look and advice if you will. Regarding rubber on the floor, i didnt mean to float the floor, just wanted to soften impact of footsteps on hardwood finish. If you think i dont need it, i will be more than happy to scrap it. I will move on to the next matter and that is ceiling. You can see from the photo that ceiling is made of concrete and its pretty flat surface. My plan was to suspend two gypsboard plates with rockwool on top of it from the concrete ceiling by using this original Knauf system with Ankorfix. Ankorfix is a system which acts like a spring and is fasten to the concrete ceiling as you can see on the picture. My intention was to connect ceiling to the double walls side because i want to errect those double walls up to the concrete ceiling. So basically i will not have suspended ceiling rest on the top of those new double walls, but instead ceiling will be joined with the sides of doublewall. Des that make any sense? I have included pictures of studio layout, space itself,and Those Knauf systems which will be used. Thanks a lot for your help

Don't put the rubber down. While you might dampen the impact noise from going into the slab, you will also be creating a resonant floor in the midrange frequencies. We laid a laminate floor down over concrete with a very thin layer of foam for the same purpose and created a much worse TL from the next room because any sound coming through the floor was amplified by the extra layer of foam. my 2 cents.... -ashley

Bassman, how did you fix that? What did you do with your floor in the end? I was actually thinking of doing exactly what you did, but since it didn't work for you, maybe it would be wise for me to do something else!! :shock: So if you fixed that problem somehow, what did you do?

Unfortunately, we are stuck with the problem. Re-doing the floor was not an option. The result is that when the printing press is running in the other room, I can hear its "clack, clack" sound more than I care to. It does not stop me from working but I don't like it either. Go ahead and use the laminate flooring but just don't put anything down between it and the concrete screed if you can. Bond it directly to the concrete. Concrete is a fairly dampened material to begin with so take advantage of it. -ashley

Thanks Ashley! Advice much appreciated. In my case, the concrete is not level (dips and bumps), chipped in places, slopes slightly, and has several oil stains and other unidentified stains. It was a garage. Another idea I was thinking of, is dumping a layer of dry sand on top of the concrete to level it out, then a couple of layers of thick plywood over that (staggered joints, etc.), with the laminate floor directly on top of the plywood. Would that be a good idea, or would the sand act similar to the layer of foam in your case?

Pour a thin layer of self-leveling cement to even it all out and then just glue the laminate down to that! -ashley

You are actually the second person to recommend self-leveling cement! There is wisdom here.... :) So, I need to call around and find out if I can actually get "self-leveling cement" here in Chile. If not, what is special about it? What makes it "self-leveling"? Is it just the mix, or is there something extra that they add to it? However, I didn't mention one teeny weeny minute little detail: There is a sewer inspection chamber in the middle of my floor, and there is no way I can move it. I'd have to dig up half the house to run the drains elsewhere. So I'm stuck with it. And hating it, as you can imagine. Now, in the 10 years or so that I've lived in this house, I have never had to open that chamber, but I do know that Murphy's law says that if I ever cover it, then the very next day I will absolutely need to open it, to clear a blockage of some kind.... Any ideas on how to work around that? I guess I need to create some kind of lip around it when I pour the self-leveling cement, and then some kind of "lid" to put over it, with some type of seal around it. But I have no idea what. All suggestions welcome!

Guys, you are hijacking this thread. Please use PM. Bassman you are speaking of creating problem by using rubber or thin layer of foam because now you can hear stuff from the other room through the floor. First of all, are you sure noise is coming through the floor and second dont you have separate floors for each room? Cos if you have same floor in both rooms then that is cause of your problem not the rubber sheet. I would also think that laminate is just not as good as hardwood acoustically. My 0,3 cents

:o Sorry. I didn't realize I was posting about someone else's build here. But also, to answer your comments: 1. Yes, there is one floor connecting the entire space. this has been this way for 30 years or so. Not much we can do about it. 2. I had worked in the same room for over a year without the laminate flooring and had no issues with the printing press sound coming through the floors or walls to any degree. When we added the laminate flooring with the pad, the noise increased noticably. Ergo, the flooring was the problem. I believe it acts like a resonant panel to amplify certain midrange frequencies. I would again not recommend laying any sort of squishy rubber or pad underneath laminate or hardwood if you can avoid it. Any floating floor system requires a great deal of mass to make it viable. OSB and hardwood just won't cut it. 4" of concrete on springs? That'll do it! Good luck with your build! -ashley

"When we added the laminate flooring with the pad, the noise increased noticably. Ergo, the flooring was the problem. " The padding was the problem.

xSpace wrote:

"When we added the laminate flooring with the pad, the noise increased noticably. Ergo, the flooring was the problem. " The padding was the problem.

Is padding problem only with laminate or with hardwood as well? Are you saying i should glue hardwood only to the osb board and be done with it? Or even without osb board?

The laminate flooring, by design, does not attach directly to the existing floor, it is designed to float. When it floats it turns into a transmitter and passes on vibration. A hardwood floor is usually nailed directly to a wood subfloor. Well, nailed on top of 15 pound felt, directly ;) Engineered wood flooring is glued.

xSpace wrote:

The laminate flooring, by design, does not attach directly to the existing floor, it is designed to float. When it floats it turns into a transmitter and passes on vibration. A hardwood floor is usually nailed directly to a wood subfloor. Well, nailed on top of 15 pound felt, directly ;) Engineered wood flooring is glued.

Pardon my ignorance, but what is the point of 15 pound felt on the floor where there is no hydroisolation needed?

Yes, the padding as part of the flooring system created the problem. I would glue the hardwood right to the OSB. Nothing should be able to move about. That is what I think created the panel resonator in the floor. I think the same would happen with laminate or hardwood. The resonant frequency would change but it would still be there, IMHO. cheers, ashley

daiwa wrote:

Pardon my ignorance, but what is the point of 15 pound felt on the floor where there is no hydroisolation needed?

It is common(in the part of America where I am) to place 15# felt under nail down hardwood to prevent wood-to-wood squeaking. Like when you come up a older staircase that has a squeaking tread/step...it's wood-to-wood making the squeak.