The infamous Floating floor Thread

From what I’ve read recently, there seems to be a lot of peoples that are still lead to think that (wooden)floating floors are the best and only way to go to achive the best results. Even after reading some of the posts here I tought too that was the best way to go, and did build it, only to learn afterward that I probably could have achieved better results by not floating at all. So I think it should be clearly stated in the sticky section all the why’s of it, and why we (as a group) don’t think it’s always the best way to go. Personaly I’d really like to have M.Sayers input on this issue since some of his design involved floated floors.And since he started this whole wonderfull forum of discution after all, seems logic to me that we would all go in the same direction. I am not challenging in any way M.Sayers competence, I think we would all benefit to know why in some circumstance a (wooden) floating floor was a viable option. And Steve (Knightfly) words of wisdoms on the subject would be great to hear too. We all know M. Rod Gervais great expertise on the subject, and if someone reading this thread was planning to build a wooden floating floor, get his book first and read it from page 40 (the whole book would be extremely usefull too :wink: ). Then take it from there. Only for the good of all.... Thanks

I was thinking of building a floating floor. I'm not sure exactly the term floating. I've read where to build a floating floor, they used a rubber base as a spring, and actually had it "float" above the cement floor. I can understand this concept, however, I planned on not using the spring, and just building a wooden floor off the cement. As in, Build a frame out of 2 x 4's, or whatever frame wood of choice, insert insulation into the frame, then cover the frame with 1/2 inch thick plywood, and build your walls up from that. I'm aware that you can get similar, if not exact acoustical results, and separation from not building a floating... or not floating? floor... My reasons are different though. I plan on building the floor not just for sound, but also for heat. My studio is going to be in a warehouse, with no insulation, and the cement floor will cool whether I have insulation in my studio or not. The fact that the cement floor is around the studio as well, that surrounding cement will cool, and will cool the cement inside of the studio as well. This will cost quite a bit in heating costs over time. With the insulated wooden floor, The heat will stay in the studio, regardless of what temperature it is outside of the studio. Another one of my reasons for building the floor is the look. I really don't want my studio to have a cement floor, that would not feel like home to me, and I wish to have the place I'm going to work in for hours on end, to feel like home. Also, when clients come in to record, if all of my floors are cement, it doesn't exactly look professional. Yes, professional studios have cement floors, however, not all of their rooms do, usually it is just one. I'm sure there are exceptions. So in the end, I feel a floating floor is better for me. But, if you know something I don't, please do share. I don't have Rod's book yet, so I cannot refer to it. EDIT: as an edit, I'm curious if anyone knowledgeable can comment on if this is a good idea or not. The studio is still in the design phase, coming along quickly thanks to Kendale :). However, I'd figure I'd ask this before hand anyway. The floor will span multiple rooms. If i'm not mistaken, having no spring in between the ground and the frame would make the wooden floor act the same as if it was the cement floor beneath it, correct? If this is the case, the only added acoustical benefit would be the insulation should also act as a bass absorber, although the plywood will reflect most of it back, the very lowest might get through, and the insulation would absorb it? and last question if anyone wishes to enlighten me, It would be pointless to have separate frames for each room right? Whether it is all one frame/floor, or segregated floors per room, the acoustical isolation will be the same, correct?

my 2¢. when you discover the true cost (money, time, structural work, etc) of a properly floated floor, you think "wow, there must be a cheaper way". with all things, there is, and typically that would be to use wood instead of concrete. and less elaborate spring methods, or less weight because I'm in an attic or cannot change the structure, or something else to reduce to cost to palatable. in some cases, depending on the existing space, isolation requirements, budget, time, available expertise to construct, the decision to go with wood floating floors is probably valid. in other cases, without enough details I suspect more often than not, skipping the additional cost and complexity of floating a floor is probably the better choice unless you fully understand what the tradeoffs are (reading Sharward's thread on this will definitely help). for example, if I have a solid concrete floor (5" with steel reinforcement) over a hard packed dirt and gravel base, and its 9 or 10 feet under the ground level, surrounded by concrete block walls, then chances are good I'll have minimal flanking issues to the outside through the floor or earth backed walls. I might however have issues with interior flanking if I'm recording loud music or have mechanical equipment co-located which could impact my ability to properly record. maybe then the answer is a floated floor in the live room? or maybe the control room instead (maybe isolating the CR floor is cheaper than the live room and yields the desired result?) maybe "floating" the mechanical equipment is better? maybe the overall level of the flanking is small enough to ignore it? only proper testing and analysis will determine that you have possible issues and from there what the possible solutions are. I defer to people who know much more on this topic than me but I think it is primarily that assessment and design are situational in nature as to lead to the solution. of course if budget and time are not an issue, then just about anything can be fixed...

I went to a buddies studio who had floated his floor over garage concrete. He had meticulously planned and floated it on pucks and rockwool etc... and STILL had major problems in certain frequencies that plagued his recordings. He wishes he didn't spend the extra time and money to float it, as he cannot figure out why it is not performing as supposed to. Its a conundrum for sure unless you know exactly what you are doing or have the engineering proficiency to design away the exact resonances etc you want to avoid.

Well what I was saying was not using a spring at all, just building a 2x4 frame (no standoffs, just laying the frame right on the cement), much like a wall, and laying 1/2 thick plywood over it, with insulation underneath, to preserve heat, and prevent sound from escaping. Would this affect the acoustical performance of the room? Shouldn't it just act as the cement floor considering the floor isn't actually floated on a spring, it's just lying on the cement?

CaptainTaco wrote:

Well what I was saying was not using a spring at all, just building a 2x4 frame (no standoffs, just laying the frame right on the cement), much like a wall, and laying 1/2 thick plywood over it, with insulation underneath, to preserve heat, and prevent sound from escaping. Would this affect the acoustical performance of the room? Shouldn't it just act as the cement floor considering the floor isn't actually floated on a spring, it's just lying on the cement?

The answer is "no it shouldn't". Simple right? Think about it for a moment - whether it's studs on the floor (joist really) - or studs on shims on the floor - what you are essentialy building is a series of drum heads - and however closely connected to the floor they are determines (along with other things) the center frequency of the drum head - but a drum head you will have none the less. My opinion is this- if you aren't going o do it right - and that means a design built around 10 Hz - then don't buid it at al - because if it's wrong - you can actually make it amplify certain frequencies - meaning you could be much MUCH worse off with it than without it. Sincerely, Rod

thanks, nice to hear from such an experienced person. well that is quite depressing. That doesn't really work for me lol. So there is no way around it without building a floating floor, and building it to specific specs huh. Even if the frame is tight (the joists are close together), it's close to the ground (preferably just a small lift, maybe an inch, and it's well insulated underneath? With a very thick plywood? I'm assuming that you're going to answer with, it wouldn't be as much amplification of certain frequencies, but it will still act as the drum head stated? How close am I? lol EDIT: I was talking with a friend who mentioned actually lying the 5/8 flooring plywood on the actual ground, with a layer of plastic underneath it to prevent moisture coming through. I think that's a bad Idea, but just figured i'd throw it in there.

When I get a bit of time, I'm going to start a new thread, which I'll call something like "Thinking of building a floating floor? READ THIS FIRST!" and then linking to all the threads here (and elsewhere) that discuss the issue, with a conclusion that states, as Rod so eloquently wrote, it's most likely a no-go for people without A LOT of letters after their names. And when that happens, I'm gonna' "stickify" it and/or link to it from the Reference Area. :twisted: --Keith :mrgreen:

forgive me, I did do a search for floating floors, but what it brought up were mostly finished floating floors, in which the threads don't really answer my questions. Again, ok I get it, even close to the floor the flooring will still act as drum heads. But please, just answer two questions. 1. If there is enough insulation between the flooring plywood, and the cement will this cancel the effect of the "drum head floor"? and 2. If I were to lay the plywood directly down on the cement, would this yield acceptable results? anything to insulate the room from the cement a little, to take the cold out of the picture during the winter. Plus I could then layer the plywood with hardwood. Would that work?

CaptainTaco wrote:

forgive me, I did do a search for floating floors, but what it brought up were mostly finished floating floors, in which the threads don't really answer my questions. Again, ok I get it, even close to the floor the flooring will still act as drum heads. But please, just answer two questions. 1. If there is enough insulation between the flooring plywood, and the cement will this cancel the effect of the "drum head floor"? and 2. If I were to lay the plywood directly down on the cement, would this yield acceptable results? anything to insulate the room from the cement a little, to take the cold out of the picture during the winter. Plus I could then layer the plywood with hardwood. Would that work?

Actually, If you want to take the cold out - you could apply a rigid high density styrofoam sheet (say 1.5" Dow Board- T&G) directly to the concrete - and then install 3/4" T&G plywood above that (assuming that you first applied something like 1" of GYP-CRETE self leveling topping to get yourself out of the problems you have with the uneven existing floor) - above a good quality sealer - then attach the plywood through the insulation directly to the concrete using TAPCON concrete screws. This would give you the comfort while maintaining the floor as a single leaf. That would be about an R-7 insulation between you and the concrete deck - plus jst a touch of spongyness so it was easier on your feet. Sincerely, Rod

Hi all This thread was also posted in the design Forum Here : http://www.johnlsayers.com/phpBB2/viewtopic.php?t=8135 Some might want to take a look, as it got different replies. A Note for Sharward, making a sticky about floating floor would be a blessing. me think.

Thank you rod, that sounds amazing, it's exactly what I want. It solves the cosmetics problem too, considering I can put a hardwood floor over the plywood after. I don't have an uneven concrete floor so it shouldn't be a problem One question though. Would the walls be built on top of the floor? or around it? I'm hopeing on top, this would provide the easiest construction for me. Also should I use a water seal of some sort on the concrete before hand? or put a layer of plastic down or something? Thank you for the excellent idea!

Built your walls directly on the concrete (not over the floor) Then built your floor "inside" the room, using Rod's suggestion. As for the sealer my guess is yes it should need some sort of sealer, but i am not sure about this one and i'd really like to hear about it too.

would I then bracket the walls to the floor or something? I don't know much about the construction of walls on a flat ground. Is the weight of the ceiling enough to keep the walls flat on the ground, without movement? Or do you need to screw the walls into the concrete as well, to make it structurally sound? sorry for all the questions, especially if they have indeed been answered before.

CaptainTaco wrote:

would I then bracket the walls to the floor or something? I don't know much about the construction of walls on a flat ground. Is the weight of the ceiling enough to keep the walls flat on the ground, without movement? Or do you need to screw the walls into the concrete as well, to make it structurally sound? sorry for all the questions, especially if they have indeed been answered before.

you should purchase a book on the basics of carpentry if you have to ask a question like that. You aren't anywhere near ready to build anything if you don't understand even the most basic construction requirements - and this forum isn't isn't intended to be a trade school - but rather is intended to be abvle to provide more delicate information that evades even some of the best builders. The Very Efficient Carpenter: Basic Framing for Residential Construction By Larry Haun is a pretty good book to start with - pick it up. Sincerely, Rod

Thanks, however I have a carpenter that is going to help me with the building aspect, I'm basically here for understanding what needs to be considered in the acoustical aspects of construction. I also have a decent understanding of construction, however I have never built on concrete before, it has always been additions to housing, which was on either the second or third floor, we would screw the framing into the lower floor. With concrete it is dealing with the base, I have not dealt with that. I will try to find the answer to my question elsewhere, but I don't believe I am to unexperienced to be on this forum. Thank you

CaptainTaco wrote:

Thanks, however I have a carpenter that is going to help me with the building aspect, I'm basically here for understanding what needs to be considered in the acoustical aspects of construction. I also have a decent understanding of construction, however I have never built on concrete before, it has always been additions to housing, which was on either the second or third floor, we would screw the framing into the lower floor. With concrete it is dealing with the base, I have not dealt with that. I will try to find the answer to my question elsewhere, but I don't believe I am to unexperienced to be on this forum. Thank you

Taco, I was not suggesting that you are too inexperienced to be on this forum - only that you should consider broadening your learning methods........ With the vast wealth of knowledge available to you on the basics (in books, etc.) - I can't understand why you would wish to go through the learning process on things like that here........ Sincerely, Rod

CaptainTaco wrote:

I also have a decent understanding of construction . . . we would screw the framing into the lower floor.

Never use screws for framing! Always use nails! Cap'n Taco, with all due respect, you need to become a lot more familiar with a lot of things before you can lead effectively on your project. Sometimes it ends up we know a lot less than we do and/or think we need to. This is one of those times for you. Consider this free advice the most cost-saving and quite possibly life saving advice you'll get in a long time. Honestly become one with your limitations so you can address and overcome them. Now is not the time to pretend to be your own hero. Respectfully, --Keith :mrgreen:

yes you got me, i used the term screwing by accident considering I was talking about screwing into concrete. Again, I appreciate the insults, but I do know more than you seem to believe. I'm not trying to make myself seem more knowledgeable, honestly I could care less what other people think, but I know plenty enough to lead the project, with the assistance of my carpenter friend. I do believe we all have something to learn, and I have much to learn, but I don't believe that I am at the level that you seem to think I am. I plan on picking up a copy of rods book, but haven't gotten around to it yet. Again I appreciate you trying to look out for me, and my project, but again, I have more experience than believed. Just not in studio building :), I have no experience in that, hence me being here. Again I repeat, the project will be overseen by at the very least, one skilled carpenter, I am not going to be doing it by myself, I am just making the design, and doing the planning, everything will be overlooked by a skilled carpenter before continuing. So there is no need to worry. If you find I asked to simple of a question to be answered here, then just don't answer it. I'll ask the carpenter... sounds like a bad movie... The Carpenter, an epic thriller... staring Jim Carey? Again I thank you for any time I may have wasted, but please, try to understand, I'm not the idiot you think I am. :)

I'm sorry if my strong statements insulted you, Cap'n... But sometimes I feel as though I have to bring on the "tough love" when I get the sense that someone is marching backwards off a cliff... And, to be honest, that's honestly how I interpreted the direction you were going. I think it's fair to say that one needs to have a pretty solid foundation of basic knowlege about construction concepts in order to succeed in designing a space, let alone a studio. Not to pick on you, but that level of knowledge didn't translate in what you wrote. We really are here to help. Consider starting over with a new thread devoted to your project, following all the guidelines in the "Before You Post" announcement. :-) --Keith :mrgreen:

I have a thread devoted to my project, in the design forum. I just saw this thread, and commented on the floor i was planning, which quickly turned into this bloodbath of questions, considering rod shot my plan out of the sky with a 12 gauge shot gun. However, all is well, I'm going to do the suggestion by rod, with applying the plywood directly to the floor above a layer of HD Styrofoam. The only issue i'll have is the concrete... It isn't normal concrete, my studio is being built in what used to be an army base's warehouse. I don't know what kind of concrete they use, but it's near impossible to drill into. In all seriousness, we had to use concrete nails on a recent project in the warehouse, and you couldn't hammer them in. They would bend. I don't know about you, but that is unheard of to me. I'm thinking of alternative methods to drilling, perhaps glue, glueing the styrofoam to the floor, and then the plywood to the styrofoam. Sorry, I'm ranting. I wasn't really looking for an answer, just kinda telling the story of the nails... my thread is here http://www.johnlsayers.com/phpBB2/viewtopic.php?t=8129 and you are right, I do not have advanced knowledge of construction, but I do have the basic knowledge to get me going in the right direction, with help, and like I said, i will have a skilled carpenter backing me the whole way.[/url] To answer my own question, why should the walls on concrete be any different then the walls on wood flooring? I'm going to guess and check, but, the walls should be nailed into the concrete with masonry nails? I'd imagine this is a step the doesn't absolutely need to be done, but when building a large structure is probably wanted to be structurely sound, and to preserve isolation of sound. Fail or pass? EDIT: On second thought, I think i take back that gluing statement, I think gluing will end up turning out horribly.

CaptainTaco wrote:

To answer my own question, why should the walls on concrete be any different then the walls on wood flooring? I'm going to guess and check, but, the walls should be nailed into the concrete with masonry nails? I'd imagine this is a step the doesn't absolutely need to be done, but when building a large structure is probably wanted to be structurely sound, and to preserve isolation of sound. Fail or pass?

Yes the walls need to be solidly connected to the concrete deck - for seismic if nothing else- Even a "floating floor"isn't truly floating freely- everything has to tie to the building in such a manner that the structure has (at the least) the seismic restraint of the original building.

On second thought, I think i take back that gluing statement, I think gluing will end up turning out horribly.

Good thought - it won't work - The concrete may be hard - but trust me - no matter how hard it is - with a hammer drill - you can drill it........ just take your time - let the drill do the work - and don't let yourself get frustrated. Sincerely, Rod

I agree, I'm going to have to suck it up and drill my way through, it's gonna take a long time, and many... for lack of better word, bit. I know there is a specific name for it, i just can't remember now, and i'm to tired to look it up. Really wish you could see this concrete though, I'm sure you'd be amazed. When I get that far, I'll post a picture of my attempts at drilling. I'm sure you'll find it amusing.

Odds are your gonna find more rebar than you can imagined. I worked on construction of a new Phizer facility a few years ago, when they poured concrete for the vault for the drugs,ect it was 2' thick . The rebar was woven so tight it looked like a chain link fence. Very hard to drill through something when all your gonna do is wreck your masonary bit on steel.

jammin dad wrote:

Odds are your gonna find more rebar than you can imagined. I worked on construction of a new Phizer facility a few years ago, when they poured concrete for the vault for the drugs,ect it was 2' thick . The rebar was woven so tight it looked like a chain link fence. Very hard to drill through something when all your gonna do is wreck your masonary bit on steel.

Sometimes you're better off just using a core-boring machine (which is designed to eat the rebar) and using masonry bolts rather than nails. I worked on a factory conversion (High end apartments and retail/resturants) back in the early 1970's (Mystic Square in CT) that had a slab we needed to remove (because the floor level dropped 3') and the slab was 5' thick with number 9 bars (or something along those lines - roughly 1 1/8" rebar) on 12" centers both ways. So it was jack hammer and pick out crumbs - then burn steel with a torch - back and forth. BUT - my first wife was pregnant for my oldest daughter at the time - and it beat the hellout of the bread lines (I was a laborer in the beginning) Now those were long days....... ROd