CONSTRUCTION DETAILS. PLEASE HELP

here more details.. i have about 100 sq meter of 2.5 pcf 100 sq meter of 3.75 pcf and about 30sq meters of 8.75 pcf rockwool... my floor is 90 sq meters.. the heavy wool is almost transmiting structure born noise.. i tried knocking on it..đ what can i do with it? should i cut it in small pieces and fill up a bastrap with it?, make it more fluffy.. :) and the glass wool i have 253 sq meters of the 10 cm thick isover glass wool (the yellow one in the pics) that is 0,75 pcf.. i think.. but it has very good acoustic propertys.. very absorbent.. and i have this wool with the aluminiumlike coating.. 48 sq meters.. i have to know what where to use... what should i put in inside the walls.. what on the parts where the cloth comes over.. etc.. so i can know the exact weight of the walls i have :) Petar

Summ the questions: what is the 3.6pcf good for? The 3.6 pcf looks good for the floor, as shown in your pic - to be sure, you can cut strips of the 0.75 pcf "fluffy" stuff, about 150mm wide, and lay it centered between each joist before putting the chipboard on top. Try it both ways, you want the weight of the chipboard to compress the insulation enough NOT to keep the chipboard from touching the joists, with JUST the weight of the chipboard. Lay a piece of the chip board over 3 joists (with pucks under them) and the insulation, so you have joist/insulation/joist/insulation/joist, then lay the piece of chipboard on top. Leave it overnight, then check. If the chipboard is touching the joists (or almost) this is what you want. BTW, just because the chipboard interlocks, does NOT mean you shouldn't SEAL it; I would put a light bead of acoustic caulk into each joint, compress the joint, and wipe the excess. You need an airtight seal here. If you've not used this type boards before, you need to leave a bit of slack in joints anyway - so the caulk will ensure a good seal, while letting the boards expand slightly as they reach moisture equilibrium in the room. what is the 2.5pcf good for? This should be your wall insulation; also good for absorbers, ceiling, traps, just about anything. what to do with the layers on the wool (the black and the aluminiumlike)? The black; if you use on ceiling, put the black DOWN as you thought. Walls - doesn't matter, unless it's a SLOT resonator; then, put it closest to the slots, up against them. No need for cloth covering that way. The silver stuff will act as a vapor barrier; so don't use it anywhere that both sides of the wall or ceiling aren't at similar temperatures, or it will cause mold. You could use it in the ceiling if you don't have enough of the other, if you do that the silver part should go UP so you get the absorption. Specifically where you DON'T want to use the silver stuff is on EXTERIOR walls or ceilings, or on the floor. comment the doors and the chipboard Doors look good; if they are "pre-hung", check to see if the metal extrusions they are framed with have any hollow "voids" - if so, these must be filled. Here in the US, a product called "plumber's putty" is good for this. Chipboard - looks fine, see comments earlier. If you have problems getting the boards to go together enough, you can use a scrap edge cut from one of the boards as a PAD - put it into the mating edge of the board you're trying to move, and hit the SCRAP piece with a large hammer. That way you won't damage the interlocking edge of the GOOD piece. should the rubber compress 10% or 20% one time you say 20 on time 10.. i am confused You're not the only confused one - here 'tiz, as simple as I know as of today - any elastomer needs to be slightly compressed at rest, or it can't act as a spring - most manufacturer's guidelines say a MINIMUM of 5% compression, 10% is best, and more than 20-25% will SERIOUSLY shorten the working life of the rubber. Therefore, if you aim for 10% in your calculations you will be right where you need to be, somewhere between maybe 7-12%. This won't seriously affect life of the material, but WILL optimise its effectiveness as a spring. All elastomers "sag" with time under compression, this will not be a bad thing because your insulation will also; that way, you still get contact with the underside of the floor, so it stays damped. What weights to consider for your 10% target - everything that will be in the room (and everything that IS the room) ALL the time. No people though. You have the weights of each type material, now you calculate how many pieces of each, add them up, and divide by the floor area to get total surface area of rubber you need (in actual contact - don't forget that only the part the joist sits on counts) - this will give you your total contact area. If you are NOT floating the walls on top of the floated floor, you're done. If you ARE floating the walls on the floors, there is more to do yet. Let me know for sure, but it looks like you're putting the floors INSIDE the walls. all the rooms are separate.. here is the thing.. now my wall between live and CR will be 55 thick.. with 32 cm of air.. will that be a problem? can there be too much air? can i now fasten the gypsum boards on the wood framing.. since they are decoupled? that would make the wall at least 20 cm thinner.. That much air is fine, although most of it should be filled with insulation (except windows :=) - yes, if your inner and outer frames are decoupled you can mount the wallboard directly to studs on both sides. Just be careful to make sure that NO PART of one half of a double wall is in hard contact with ANY part of the other half. Are you using double gypsum over the joists in ALL rooms? If not, you will lose isolation. Above the gyp you need insulation - if you have enough, you could use a layer of the 0.75 pcf insulation on top of the gypsum, then (if it's not too thick) a layer of that 8 pcf stuff. How thick is the 8 pcf stuff? If more than about 3", this might not be a good plan - you don't want the heavy stuff to compress the light stuff by very much, like 50% or less. Did I miss anything? Steve

so i am set now.. :) should i calculate the 2nd layer of chipboard when deciding on the puck placment? because i will not put it anytime soon :) for now i planned one layer of gypsum above the joists.... but i will put two if you think it is better... the 8 pcf stuf is 10 cm as well.. ..i will first insulate all the walls in the rooms and if i have some left i will put it above the joists.. should i use the cloths in the pic before anywhere?? i will start the framing tomorrow.. thank you very very much :) (edit - I'm adding this from a PM so others may see - ) and one more thing.. that is "leave slack" in the chipboard comment mean Petar p.s. you didn't answer if the soffit wall goes on the floating floor.. and where can i find info about how wide it should be.. how thick.. and before all how much it weighs.. so i can calculate it when placing the pucks.. the pucks should be centered at what distance? 24"?

should i calculate the 2nd layer of chipboard when deciding on the puck placment? because i will not put it anytime soon Either that, or calculate for 5-10% deflection; then, when you add the second layer it will still be right. If you don't add it, you will still be within the proper range of compression. for now i planned one layer of gypsum above the joists.... but i will put two if you think it is better... Definitely two - you do remember you wanted good isolation between the CR and live room, right? the 8 pcf stuf is 10 cm as well.. ..i will first insulate all the walls in the rooms and if i have some left i will put it above the joists.. As thick as the 8 pcf stuff is, I'd not use it if possible, period. It's too heavy for the ceiling, too dense for surface treatment, too uncompressible for floors... should i use the cloths in the pic before anywhere?? Those, if they are the right color for you, could be used behind the slats in the parts of your walls/ceilings that will be spaced apart for slat resonators. i will start the framing tomorrow.. thank you very very much (edit - I'm adding this from a PM so others may see - ) and one more thing.. that is "leave slack" in the chipboard comment mean If you leave no space for flooring sheets to expand, they will likely BUCKLE as they age, leaving your floor WAVY. It's generally recommended to leave them NOT tightly meshed, about 1/8" gap is typical recommendation. This will leak, so needs to be caulked. The caulk will "give", allowing them to shift some. Petar p.s. you didn't answer if the soffit wall goes on the floating floor.. and where can i find info about how wide it should be.. how thick.. and before all how much it weighs.. so i can calculate it when placing the pucks.. I didn't answer this part because I haven't finished working out details yet; both you and Aaron are in need of this, although his will need to be slightly different. I need more time. the pucks should be centered at what distance? 24"? The pucks should be under the joists (obviously :=) Spacing is what you are calculating. If you cut the pucks to a specific size, you will know how many square inches of contact surface they have where they meet the joist - for example, with 50mm joists (2") a 1" wide puck would have 2 sq. inches of contact area. If you can depress that puck by 10% by placing a TOTAL weight on it of 20 pounds (1 kG = 2.2 pounds) then the pucks need 10 pounds per square inch of contact space. So, if your total floor weight is 1800 pounds, you would need 180 square inches of contact area. Using the above puck size of 1" wide, or 2 square inches, you would then need 90 pucks total. If you then had 168 lineal feet of floor joist, this would put the pucks 1.86 feet apart. In reality, a puck that tall should be wider; if you double the width, you would then need 45 pucks (in this example), which would be spaced 3.7 feet apart, which is still good spacing for that size joist and loading - Now, if you were building your walls on TOP of this floor, you would want more support under the wall - so you would ADD more pucks under the wall section, calculated on the added WALL weight. If your ceiling were ALSO floated on these walls, that weight would need to be averaged along the wall length and added to the total sprung weight. This puck material is something new - any specs on it? Or is it the SOFT stuff you mentioned earlier in your thread? Steve

no it is not soft.. :) it is from the rubber company.. to compress 1 sq meter of this material there has to be a surface load of almost 8 tons.. but when you press it with your finger tips it goes down easly :) so it is pretty good for this kind of usage.. :) i am sure that it will be very good :) Petar

Greetings, Petar -- I've been quietly watching every move you're making... Wow, quite a project!

Spock wrote:

to compress 1 sq meter of this material there has to be a surface load of almost 8 tons . . . it is pretty good for this kind of usage.

Do you know the weight of all the materials you're going to be putting on that rubber? Not just an estimate rounded off to the nearest TON, but a careful analysis of the weight of everything? You do understand that there is a huge risk of overloading, just as there is a huge risk of underloading, don't you? :shock: Over the next couple of weeks I plan to do careful testing of my rubber, as well as extremely careful analysis of the estimated weight of all my materials, to make sure that I load the rubber "just right." This is not something you can be pretty sure about -- you have to be absolutely 100% positive.

yeah i know.. i just said how much the sq meter can handle.. i was testing one sq inch :) i pretty much knowall the weight.. but you have to bare in mind.. that if 5 people are in the room the weight changes for about 400 kg and my wally weigh so much :) ..so it is very hard to estimate it right.. :) my first move is not to cut the wood in the right pieces.. and then we will go further :) i will post pics tonight

here my update.. please comment as soon as possible before i go one day more with mistakes :) i estimated the floor weight of back part of the control room on about 552 kg and the front part on 344 kg.. my puck 5x7 can hold 10 kg to compress from 20mm to 18 mm (10%) (the area that touches the josit.. the 5x5 area) in the end it was 30 cm centers for floor behind.. 55 cm for the floor in front.. and around the edge (where the wall will stand on the floor) 15-20 cm spacing.. and here is how it looks like :) wall partitions are about 100 kg per meter.. the spacings i used here where the door comes.. ..then gluing them under the joists then pulling the cables on the floor and then putting the boards and wool.. i tried that with the 0.75 pcf strips.. but the board is then way high.. so i went without those.. i put the a bead of caulk in the interlock crack and then pushed the boards togeather.. i hope that is ok? i screwed the OSB boards 30 cm centers to the joists.. with the same screws as i use for the gypsum boards.. this i think was good... the whent nicley in.. and fastend it preety good.. i have this extention on my screwdriver.. when it goes a little bit in then it won't go anymore so you don't drill a hole trough the gypsum with it.. it was very good for the osb boards as well.. the srew head sinked just a little bit :) one thing.. when you walk on the boards.. it feels a little bit soggy... like the floor is mooving.. maybe that is so because of the elastomer and the wool that didn't settle???.. yet.. around the cables on the floor is that acceptable.. or common or is that a great mistake?.. maybe when all the equipment is in place. the boards wont moove so much anymore? what is your advice.. is the way i am doing this ok? Petar

One thing you may need to do is run "stringers" or cross braces between your floor joists. This will tighten up those long spans you have. Looking at some of those pix (and it may just be an optical illusion), it looked like a couple of your joists were not level. Did you check to see that the floor was level in all area's?

my floor is not in level.. so my joist are not also.. i didn't check that though.. it thought if i put the neoprene ruber under it.. that it will level out the uneven parts.. what do you suggest i do? or how should i level the joists.. you think if i put stingers that the floor will not move so much? is your floting floor moving? some of my joists are not very straight (wood is not straight.. so i have to screw it to the board to make it straight.. so stingers is a must? or is it ok if it moves a little bit? i thought the boards would make the studs tight.. please help on that one

Spock wrote:

my floor is not in level... so my joist are not also.. i didn't check that though.. it thought if i put the neoprene ruber under it.. that it will level out the uneven parts..

Alarm bells are ringing in my head. :shock: Do you hear them too? You're not using the Neoprene for leveling; you're using it for decoupling/floating. In order for rubber to level things out, you'd have to overcompress the rubber in the high areas and undercompress the rubber in the low areas. That means your decoupling will be failing in those areas or will fail sooner than the other areas. Failing = flanking = leakage = bad news. In my design, I also have an unleveled floor - I will be using wood legs of varying heights with rubber (EPDM) pucks underneath them. The wood legs are for leveling, and the rubber is for decoupling. I worry for you, Spock... Please: for your sake, slow down. Or am I overreacting to this? Guys, please... Back me up or challenge me.

Kieth is right; EVERY ONE of your pucks should be compressed at static load by the SAME AMOUNT or they won't do their job, which is as Kieth stated. You need to use SOLID material for leveling, so that ALL your pucks are doing is acting as PROPERLY LOADED springs. Period... Steve

From the REFERENCE section, check the first pic you come to - notice what's different about this framing? These are the "stringers" or cross-braces that will stiffen up your floor. You may not need quite that many, but at LEAST every 8 feet, 4 or 6 feet apart would be better - http://www.johnlsayers.com/phpBB2/viewt ... &start=120 Steve

my floor is not in level.. so my joist are not also.. i didn't check that though.. it thought if i put the neoprene ruber under it.. that it will level out the uneven parts.. what do you suggest i do? or how should i level the joists.. you think if i put stingers that the floor will not move so much? is your floting floor moving? some of my joists are not very straight (wood is not straight.. so i have to screw it to the board to make it straight.. so stingers is a must? or is it ok if it moves a little bit? i thought the boards would make the studs tight..

If you look on my thread that Steve posted a link to above, I had nearly a 3" fall from one corner of the CR to the other. I had to level mine. I used a laser and marked the four corners of the room, chalk lined it, then used another laser ($20 from Sears) that shoots the straight visible line around the room. Found my center point. Measured from the top of the rubber, to where the laser hit the tape measure and cut blocks to fit between the rubber and the bottom of the floor. Some were 2 7/8" and some where 1/4". I used Liquid Nails construction adhesive to glue the support to the joist & rubber. With the cross braces, it sturdied the floor tremendously. This floor is built like a tank, and I feel sorry for the person that ever tries to remove it. :shock: Also, as far as the spacing between the stringers, I found that in one corner where I spaced them about 4 feet, I had some structure born "Thud or boom", so I would probably space them closer. In area's where they were 12"-24", not a problem, and very solid. Hope this helps.

hey.. here is my deal.. my floor is from one side of the room to another maybe most 3/4" diference.. and this is for me not so much of a problem.. you can't see it with your bare eye.. ..i tried to put the blocks under.. but then my blocks would have to be very small.. and this gets problematic.. then when my wool is on the floor i doesen't level in with the studs.. ...i decided that i will sacrifice the 3/4" only if it makes a major acoustic problem.. then i will make it better.. ..i agree with the stingers.. unfortunatley i didn't put it in the control room.. but i will in the other rooms.. here is how the CR room looks like it is preety good.. :).. i am satisfied (not very but satisfied :) ) but i think when you put walls around and the weight of the equipment and the second layer.. that it will be a different story :) here some more pics.. and what keeps us going :) you can see the pucks in very short spacing under where the wall will be.. the floor in the dead room will have stingers :) my brother is adding gain on the mixing console :) hehe my floating floor goes only to the inner frame of the bass trap in the back of the room.. i thought i will put the heavy 8 pcf wool on the floor in the bass trap.. and .. is it ok like this?

Are you putting walls on this floor? Here's my concern, without the extra support, and without strings adding support the other direction, you're probably asking for trouble by having it collapse at some point. If that floor is moving now (haven't seen the video yet) once you add a few more thousand pounds, it may buckle. That would be my concern (but I'm not a structural engineer either.) Wait for Steve to reply to this. As far as the insulation not touching, I don't know how much of my thread you've read, but I used some poly string and weaved it across in the spaces between the joists to help hold it up. Worked well.

ok.. sombody watch the moovie.. ..steve.. tell me if the 3/4" is a problem.. if not then ok.. ..and if the floor as on the movie is a BIG problem.. then i will tear it appart and put stingers in it :x Petar .. geting more :idea: every day

Petar, I have to agree with Aaron on this - watched the movie, and that's kind of scary. You really need to get stringers in there, just a perimeter joist across the ends of all the other joists is NOT enough. I know you're in a time crunch, but please remember that doing things twice takes even LONGER; even if you are SURE about the next step, you should ask first to avoid this costly tear-out. By now, I think several of our regulars are watching as well as I am, so you should get some sort of answer really soon after posting. And I'm keeping an eye out as much as possible, even though I'm working on several paid projects. If you dont' care about a 3/4" slope on your floor, it's not a MAJOR thing - although if the floor is STRAIGHT but just not level, you could use some thin veneer as "shims", and space your pucks slightly different from the calculated distances in order to use 1. 2. 3. 4. 5. 6 layers of, for example, 1/8" thick veneer as you travel from one end of a joist to the other. Here is a rule of thumb that has served me well over the years, I hope you can benefit from it - GOOD FAST CHEAP Pick any TWO - you can NEVER have all THREE... Steve

ok... i believe you.. but i am not changing my mind... i wan't to do it all over again and soon :) ,, hehe joke. :wink: i will tear it apart.. :? .. i believe you.... but i will make the other floors..(live and dead) first.. and then i will get back to the control room.. i want to see the difference :) thank you very much again for helping me around that.. :) one other thing is that my osb boards are not exactly sitting on the joists.. i think that at some parts it is sitting on the rockwool.. and that is why it is maybe mooving so much.. and when i screwed the boards to the joists.. my joists went up (lifted up from the floor)... i will slow down and make it as it should be :) Petar

"and when i screwed the boards to the joists.. my joists went up (lifted up from the floor)" This doesn't sound good; you may have too much compression on the insulation in that case. Is this just with the boards over? How much more weight will be placed on that floor? Will any walls be resting on the floated floor, etc? If not, you may need either a small spacer under each puck, or thinner insulation, etc - generally, the floor panels weight by itself should compress the insulation enough so that the panels TOUCH the joists. IF the panels are lifting the joists off the pucks, it is NOT good... Steve

all the walls will be placed on the floating floor.. that is why i was not concerned.. ..my walls weigh 100 kg per line meter... so if i would put them around, they would compress it so much that the floor would get very stiff.. i don't know.. what do you think? ..i will make the dead room now.. and then we will see :) Petar

I think that if you don't add stringers to that floor, you will be very sorry when it falls on its side. But your idea of doing the other floors correctly for comparison won't hurt... Steve

Spock wrote:

. . . my osb boards are not exactly sitting on the joists.. i think that at some parts it is sitting on the rockwool . . .

Quick question: Does each board have at least two parallel edges fastened to joists? In other words, is any OSB board corner not attached to a joist? I'm concerned there may be a "diving board effect" if there are boards without enough edges fastened to joists.

Are you using Tounge & Groove OSB? This would be the best for at least the first layer, that way they "interlock" two sides of the board. Don't run the OSB parallel (the long edge) w/ the main joists. Break all edges (even if you have to trim) on the studs. Scroll about half way down here: http://johnlsayers.com/phpBB2/viewtopic ... &start=135 This should give an idea what I mean.

ok.. thank you for your help.. i use tounge and goroove.. and they interlock :) .. will make some diagrams of how i placed the boards on the joists in the CR.. and how my joists will look in other rooms :) Petar