CONSTRUCTION DETAILS. PLEASE HELP

Petar, sorry if we've already covered this but I'm really behind in too many things to look through everything - do you have access to any sort of resilient mounts in your area, such as RSIC clips or Resilient Channel - if so, these could be used to isolate your INNER ceiling and walls from the hard framing. These are RSIC clips - used with "hat" channel, one side of wall only (different models for different framing types) http://www.acousticalsolutions.com/prod ... /clips.asp RSIC clips can support up to 36 pounds each, so you would need to space them about 2 feet apart in one direction and 3 feet apart in the other direction, in order to support two layers of 5/8" gypsum wallboard safely. This would put their cost at about $1 USD per square foot of ceiling, plus any cost difference in your country, maybe a bit more including the hat channel. There is more info linked on that page, you should read ALL of it before going any further - All I'm seeing for wall frames are these posts placed several feet apart - what do you intend to put between them, and how? This looks NOTHING like the CAD drawings you first posted, so I'm not sure what to tell you for your walls yet... Steve

hi, i tried to figure out some things.. :).. i know where i went wrong.. but i can't fix this without tearing the whole wood cpnstruction apart and starting almost from scratch.. would you advise that? my budget is also kinda 0$ (but i bought all materials now :) ) ..the posts you have seen in the pics are not framings for the wall.. they just hold the ceeling.. ..so my ceelings are connected with eachother.. . bummer.. :( I understand your sway braces concept totaly now.. i have experimented a little bit with knocking on wood when connected and when disconnected... you know how different it is :).. but i can't find any in the shops arround.. that is my problem.. i couldn't find resilent channels.. so i have the idea of puting neoprene strips under and above the joists.. ..puting gypsum boards on top of the joists and wood finish under the joists. here is a pic of the concept of course it will be done nicley and not as on the pic :) the neoprene strips.. 3 mm thick.. this neoprene i haves specs.. it is long lasting and good durometer.. (i understand this now :) ) it helps a little bit (when i put my ear on the gypsum board and knock on wood it not so intense as when it is directly on wood).. i don't know how good the RC decouples.. (can you still hear knocking when there is a RC in between or does it just lower the noise? ) i had to solve another problem as well.. i ended up puting the ceeling plates on the joists.. (and the joists are connected troughout the construction as shown on the bectures in previous posts) this is the right bass trap ceeling of the CR :) i ended up puting a double layer of neoprene strips under the spots where the ceeling plates and joists come togeather.. the problem is... i still had to fasten them to the joists with screws... i didn't see any other solution.. here are pics of my progress.. please comment my neoprene strips idea?.. at least the woll will be good.. it is in bales.. so i can put i continuous strip from beginning to the end if the wall or ceeling.. and it has no air gaps :) i went with metal framing after all.. i could't find good quality dry wood studs one more pic of the wool.. it is cool because it is not causing any irritation of skin at all.. (when you touch it, it doesen't have that dust in it so much) an example how the wall framing isn't all the way connected to the wood.. (except the screws and neoprene strips of the ceeling plate that is conncected to the joists) i am putting two beads of acryl sealant under the metal baseplates and i bought some special elastic plastic (i think this is what they call acoustic sealant in usa) sealant that i will use in the places where STC is most important.. (on the walls between CR, Live room and Dead room) my major faulire is not the best decoupling! can you give me a rate in db how much this will affect me? maybe this will give you an idea on how the walls will be (decoupled from the wood framing as much as possible) is wood finish for the ceeling of live room and CR ok? :)

and please answer soon if possible.. beacuse i am working on the studio every day for 8 hours.. and i plan to finsih it till 28th of february.. so as quick as the reply.. the sooner i can make changes to the ideas.. unfotunatley i have a tight schedule.. after 28th it is back to college .. and then i will never finish it :( so fast help and suggestions are welcome :) i don't want to end up like you (your wife knew which song you played on the piano in the studio :) ... from her kitchen.. ) ..i laughed when i read that.. all day.. it was kind of a sad laugh.. because i have the feeling that the same destiny awaits me too..

hi, it's me again.. another day is over.. ..i was in better mood today.. this neoprene strips have some effect.. here is a pic - top side of the wall separating the live room (left) CR (right) as you see the framing for the walls will be the steel studs.. and the ceeling is out of wood.. i put neoprene strips between the steel plates and the wood joists.. my grandpa was drilling holes in the wood on the left (in the live room) you could feel a strong vibration in the wood but the vibration in the steel plates is only 1/2 or maybe even less comparing to the vibration in the joist.. (i was testing it with my hand :) ) here one question.. ? should i run the gypsum boards of the walls all the way to the upper gypsum plate? (the one you see on the pic) or should i run them only to the wooden finish under the joists? i guess the it would be better to go all the way up.. so there is a solid barrier between the CR an the live room.. even in the ceeling part.. since they are not 100% decoupled.. here one more pic of the wall on the upper pic.. but marked on the floor ..and here more pics of how i used the neoprene strips.. and here a pic how one of the double wall goes to the josit and one (the right one) all the way to the existing ceeling.. (john said i should do it so) i still await the replies and comments.. on monday we start with covering the ceeling with gypsum boards.. :) Petar

Petar, couple of sketches with comments - let me know what else you need - sorry for the delay, it's been anything but fun around here lately... Steve

thank you so much for the reply :) i really needed it! here is the thing.. the existing ceeling is concrete.. and i am not planning on putting anything on that ceeling.. that is why i thought the gypsum above joists would be first leaf.. then isolation and then under the joists 12mm wood finish would be second leaf.. but i can but cloth under the joists and 2 layers of gypsum above joists.. (pleas confirm) :) the joists of the cr and live room are put only togeather.. they are not nailed to eachother.. ..they are only resting on the same frame... and are nailed to the frame.. does it make any diference? ..it is true when the live room joist is vibrating.. there is not so much vibration on the CR joist next to it..:) (comment) :) Petar p.s. hope for a soon reply :)

I know you're in the middle of things, so I'll try to keep up - the existing ceeling is concrete.. and i am not planning on putting anything on that ceeling.. that is why i thought the gypsum above joists would be first leaf.. then isolation and then under the joists 12mm wood finish would be second leaf.. Actually, if the existing ceiling is concrete THAT is your first leaf - this makes the gypsum above joists your SECOND leaf, and anything UNDER the joists would be a THIRD leaf. So, if there isn't room to physically get up there and add a second layer of gypsum on top of the joists, you would be better off if you can find heavier panels for that single layer - However, if the outer ceiling is concrete, and it is SEALED AIRTIGHT, and it is several inches thick, then even a single layer of gypsum with that wide a gap would give enough isolation that it won't be a problem; if that's the case, you could just put lots of insulation on top of the gypsum that's on top of the joists, and consider any acoustic treatment afterward. A lot of people tend to think only of what THEY ADD to a building as being significant; this simply isn't so. The ENTIRE structure has to be taken into account when figuring out what will happen acoustically - so, if there is already a center of mass (the concrete ceiling) then you should only put ONE MORE center of mass in place (with its separating air/insulation gap), and then any acoustic treatment you need inside that. Also keep in mind that some acoustic treatments will WEAKEN your sound proofing somewhat by actually BECOMING a third leaf - panel type bass traps will do this, as will helmholtz resonators. but i can but cloth under the joists and 2 layers of gypsum above joists.. (pleas confirm) Yes, this will work fine. the joists of the cr and live room are put only togeather.. they are not nailed to eachother.. ..they are only resting on the same frame... and are nailed to the frame.. does it make any diference? ..it is true when the live room joist is vibrating.. there is not so much vibration on the CR joist next to it.. This may lessen the flanking that will happen between live room and CR - if there's room, you could even add some of the 1/8" neoprene between each pair of joists to keep them from touching other than where they rest on the wall frame. Did the sketches help clear up any of your other questions? If not, please post back; I will be available part of tomorrow as well, then I start more 12-hour shifts. You had so many things to work out that I briefly considered a phone consultation, until I found out it costs at least $14 per minute to call your part of the world - so hopefully we can get your concerns straightened out this way, saves more money for supplies :? Steve

hi, here the progress for today.. :) but first the CADdrawing.. so you see what i am talking about. my concept was to seal of the CR from everything else.. that means sound cannot get in the CR (because that is important to me.. that i only hear what comes out of the speakers.. (then you can make the best sound) that is why the CR has heavy walls and everything.. and other rooms don't we started building the live room wall that separates the live room from the guest area (on the CAD lower right-.. we didn't go here on heavy isolation.. the point was just to separate it so the talking in the guest area doesen't affect the recording.. this wall i think has abut 48-50 STC.. or less :) as you can see the door space is there. we had the problem of the 2 joists and the wooden frame going trough the wall.. should i seal them with the sealant or just put gypsum around it and wait for it to fasten.. i think that gypsum is better since i want to use the expensive sealant for the CR room.. i can't avoid flanking here because some of the steel joist are in direct contact with the wood... but this is the live room wall.. i will watch out more for the CR i bought 7 solid core wooden doors.. and will modify them to make them totaly airtight.. (even seal the keyhole :) ) we will use them as shown on the CAD drawing the layer of gypsum boards (15 mm) is on the joists.. as you can see we added this wooden holders (screwed from above where the gypsum boards meet). the gypsum boards didn't always meet on the joists because our gypsum expert :) (my fiances father) said if you build them like a brick wall.. not in the same order, that they are stronger.. so our gaps are always on different positions.. every row diferent.. like a brick wall. naturaly screwed the all the boards on all the joists -screws 8" apart i think (or even less) the gypsum above the joists.. here is where the ceeling and the wall meet.. we could't go with the 1/4" gap here because the gypsum boards where not resting on the joist for like 30 cm or so.. so we screwed a wooden stud to the wall and screwed the gypsum boards form underneeth on the stud.. so the boards are now sitting tight.. we will follow the rule of 1/4" gap between the live room and the CR.. i have windows peaking out of the ceeling.. i will put gypsum boards over those parts and seal them with gypsum or a sealant.. (gypsum boards over the windows holes) where the gypsum boards meet the wall on the right (the small space).. i put gypsum and made the gaps airtight.. if it breaks.. i will go up again and will put sealant.. i didn't put selant because it was such a small space and some gaps where even 3/4" so the sealant would just fall trough.. i guessed for the live room it is only important to be airtight here will come the part the knightfly drawed.. the walls will go trough the joists about 50 cm and then the gypsum boards and the walls will meet, 1/4" gap .. later sealed.. one more thing.. i was not planning to put mineral wool above the gypsum boards.. to cover all that space it would cost me a fortune.. at least 2000-3000 dollars.. like 50% of what i spent till now.. i plan to put wool under the gypsum board.. i bought high density specail acoustic wool with an aluminium coating on one side.. (the company said that this was for better sound isolation) the aluminium should face the gypsum boards they said.. what do you think? there has to be a better way to block the sound from going trough the ceeling into the control room other than putting a ton of wool above the joists.. i can put a double gypsum layer on the CR side.. or something like that that is how we do it here in croatia.. :) this is the live room.. the 10 cm wool isolation between the steel studs is missing and one layer of 15 mm gypsum to cover it aswell.. i planned on puting a basstrap here in that corner.. so later you wont see that wood construction in the corner.. for now i have no budget for isolation of the left wall with windows.. a tricky part that couldn't be avoided :( now i have this wood finish.. and you told me not to put it under the joists.. but to go with cloth cover.. is that only for the CR or for the live room aswell?.. can i put it on the walls? (the ones in the live room with the windows?) ok.. hope for your reply right away :) hehe we are working tomorrow on the CR window frame and the framing for the CR walls

If you can't put insulation on TOP of your gypsum inner ceiling, then you need to use it UNDER - without it, those panels will ring and cause serious coloration of sound. One possible way would be to do a complete, slightly compressed FILL of the joist cavities, then put your boards up - this will cause some isolation loss because of triple leaf, but if your outer ceiling is concrete this may not be a problem. I would go ahead and put the boards up as tongue and groove, like they were intended, for the section over the mix area - Over the rest, you could install the boards keeping a GAP between each, (length-wise, not end-to-end) alternating 1/16", 3/16", 5/16" - this would give a slat resonator/diffusion effect over the range of frequencies from around 100 hZ up to about 250 hZ figuring your 2x6 joists. You would need to cover this area with cloth before putting up the boards, or the insulation may poke through - also, the cloth is necessary for the helmholtz calculations to be close. The doors you show look to me like raised panel doors - are they quite a bit thinner in the center than at the edges? If so, I hope you can return them - what you need for decent isolation is MASS, so a solid core door in this context means THICK EVERYWHERE, but without a hollow center like cheaper doors. I've got to say that so far this is the worst case of terms not meaning the same in different countries that I've seen - hopefully we can straighten most of this out on Friday... Steve

hi, believe me.. i called and searched an went trough all the shops.. :) this is the thickest solid core door i could find.. ...it is an exterior (entrance) door.. so they said.. it is not so thin in the middle maybe 3 cm and the outer rim about 5.. but i will measure it till friday.. my idea was to modify them.. add a gypsum layer on them a layer of wood finish on both sides.. would increase the mass of the doors.. ..and there is a guy who puts isolation in it and covers it then with a lether fabric.. makes them even thicker and heavier.. i got them for about 150$ that means about 1000$ for 7 doors.. if i made custom solid core doors (very thick).. it would have cost me 1000$ for one door... ..i planed to put 10 cm thick isolation between the joist.. (under the gypsum) all the way. and it will sit pretty tight because it is a little bit wider than the joist spacings.. i hope it will work out.. we don't have the problem in terms.. we have the problem that my country is anti acoustic isolation orientated :) i understand pretty much everything you say.. but the problem is, i cant find it anywhere..

it is not so thin in the middle maybe 3 cm and the outer rim about 5.. but i will measure it till friday.. my idea was to modify them.. add a gypsum layer on them a layer of wood finish on both sides.. would increase the mass of the doors.. This will ONLY work if you have ZERO AIR GAP THROUGHOUT THE DOOR - if your extra layers leave any space that is air or insulation, this will HURT isolation at lower frequencies, not help them. What you describe doing, sounds like a triple-leaf door to me. If you use TWO of these on a double framed wall, you will have a m-a-m-a-m-a-m-a-m-a-m construction, and although nobody I know could calculate exactly what will happen, they would ALL tell you it's BAD... if the thinnest part of those doors is about 30mm, you'd be better to just use them as they are and concentrate on good SEALS instead. If you can get thick felt in your area, this can be added on 3 of the 4 edges of the door AFTER it's hung - you mentioned filling the holes, do you have a plan for latches? In non-security doors, good compression seals and heavy door-closers can work, then you only need a surface-mounted handle to pull the door open from inside (no penetrations through the door this way) Here is what I'm talking about for a door closer - I installed a similar one on my back door (doesn't always latch when closed easy, so my dog would push it open and it would stay that way til someone discovered it, lost a lot of heat that way) http://www.asian-hardware.com/imgbig/hg-006.jpg These are usually rated by number, the larger the number the greater the force. Mine is a size 4, I think 5 or 6 is the largest. Note in the picture the two screws on one end of the housing? one adjusts the rate of close for the main part of the swing, the other adjusts rate for the final few inches so the door can close slowly at first, then accelerate enough to latch at the end. Mine was for up to 150 degree opening, and I only needed a little more than 90 degrees so I mounted it further from the hinge to increase the pressure - this would also help in a studio door if the closer is providing the pressure to seal around the door. Mine cost about $50 USD and is made by Ryobi. There is no cheap way I know of to seal the BOTTOM of a door, without having some kind of cleat you have to step over when going through - for a commercial facility, this is a BIG no-no and will even cause problems for a non-commercial one. It is, however, a cheap and effective way to seal. You just put a 18mm board across the floor where the door closes, so there are stops on all four sides of the door - then you use felt seals same as the other three edges of the door. All 4 of these should be added AFTER the door is hung, so you can adjust the amount of "crush" on the felt seals all the way around the door. Otherwise, the seal won't be very good. The more correct, and more expensive, way to seal studio doors is this http://www.acousticalsolutions.com/prod ... l_kits.asp You should download this entire PDF also - whether you use (or can even GET) their stuff or not, it's educational - http://www.zerointernational.com/educat ... sb_pdf.pdf Check out page 16 (cam lift hinges) as another alternative to a drop-seal - a compressible seal on the bottom edge of the door can be used, then when the door closes the hinge allows it to DROP onto the seal, leaving the doorway CLEAR to walk through and still get a good seal. These will support up to 500 pound doors. Here's their list of international distributors http://www.zerointernational.com/agenci ... _sales.asp ..i planed to put 10 cm thick isolation between the joist.. (under the gypsum) all the way. and it will sit pretty tight because it is a little bit wider than the joist spacings.. i hope it will work out.. Unless the insulation is about 20mm THICKER than the cavity, it will NOT work out. Gravity is NOT your friend here, you need COMPRESSION (not too much though) to keep the insulation in contact with the gypsum or it will SAG, allowing the gypsum to ring. If you use the spaced boards idea (helmholtz effect) and a cloth cover UNDER the insulation before the boards go on, you can cut strips of insulation that are maybe 1/3 as wide as each space between joists, and add these down the center of each cavity before putting the cloth on - this will stretch the cloth a bit, but the boards will take care of that. Using a full, slightly compressed fill with spaced boards will change the helmholtz action slightly so the calculator doesn't work quite right, but that's part of why I suggested to use variable spacing between boards; that way, you get a wider range of frequencies that absorb, so there won't be any peaks at one frequency. Another thing I noticed in a few spots - if you want isolation, you need NO CONTACT between surfaces. IF you put neoprene between things to keep them from contacting, you can NOT put screws through the neoprene into both objects or else the neoprene becomes nearly WORTHLESS - where you've fastened your steel framing to the wood using neoprene with a screw through it, the only thing the neoprene will do is to help keep the joint from RATTLING or buzzing - the screw will pass sound vibrations right through from the metal to the wood, or vice versa. This drawing is one way Kinetics uses to get resilient mounting - notice that there is NO PLACE where one piece of metal directly touches the other - That's not all, we can cover more tomorrow when we talk - I may have a way for you to get back more iso between CR and live room if it's not too late... Steve

RM Studio

hey :) petar here.. my father came home from usa and said that if we something.. we should do it right :) ..so we are changing the wood framing.. and are making three separate wood structures (dead room, CR and live room) nothing will be connected.. :) and then we are floating the floor.. 20 mm neoprene pads (that i put under the big wooden studs) they will be 60 cm centers like in the SAE construction manual.. studs will be 50 cm apart and inbetween 10 cm rockwool.. ..and i will put on top one layer of 18 mm chipboard (that has the connections like laminate, so you can connect them without cracks) and then the inner walls on top of the floating floor.. :) i also returned the wooden doors.. and got balcony heavy glass doors that are sealed all around :).. they are twice as heavy as the wooden i had :) they have a metal framing.. ..what do you think about the walls on the floating floor and the floating floor idea itself? (in my situation) i apreciate a quick reply.. :) since we are starting changes on monday :) what should i bear in mind? :) p.s. unfortunatley no pics.. i will have them on monday!

Just so everything stays in one place, here's my PM answer to Petar from a few days ago - I think you'll be happier doing it that way - you should at least float the CR floor, then others if/when you can. That will give noticeably better isolation between CR and others, so you can hear mics instead of walls. If you can possibly do it, I would use TWO layers of the 18mm chipboard on the floor; more mass = lower resonance = quieter, tighter sound. If not, be SURE the insulation under the floor has some compression (not more than about 15-18mm) so it dampens the floor or it will RINGGGGG... And this time remember that putting neoprene between things does NO GOOD if you then drive a screw or nail through both of them. Keep your old thread up to date, and I'll do everything I can to make sure I stay up on it; if I forget something, REMIND me but please don't do things you are not ABSOLUTELY SURE of without asking me first; I really want you to succeed in this, probably almost as much as YOU do... Steve

here a quick question.. i read some of the aronw floating flor over basement concrete.. and: i have no moisture problems at all.. can i put the 2 cm neoprene strips under the 8 cm studs (5x8) and then i put the rockwool 40kg/m3 ) i don't know how much pcf that is.. :)) directly on the asphalt.. (without the chicken wires you advised for aronw) then the total of rockwool is 10cm and total of studs plus neoprene is 10 cm and when the neoprene goes 20% down, the rockwool will push against the boards and there will be no ringing.. what do you think? or shoudl i find like 5x7 studs for more compresion of the rockwool? i will put one layer of the 18 mm (1.8 cm) chipboard in the live room and dead room.. (to expensive for 2 layers..) maybe i can put a layer of laminate some day later but i have enough particle boards to cover the CR.. should i do a 2 layer floor in the CR.. first layer particle board and second chipboard :)? i think the particle board is 20 mm.. but i am not sure.. what do you think? one more thing.. if my walls will stand on the floated floor edges.. should i put more neoprene strips around the edge of the floated floor or should i put them evenly troughout the floor? thank you

i have no moisture problems at all.. can i put the 2 cm neoprene strips under the 8 cm studs (5x8) and then i put the rockwool 40kg/m3 ) i don't know how much pcf that is.. ) directly on the asphalt.. (without the chicken wires you advised for aronw) 40 kG density is same as 2.5 PCF - divide by 16 to convert from kG/M into PCF. I don't think that is quite enough compression for the floor; but instead of trying to find narrower joists, it's better to just add enough extra insulation between joists so that the flooring compresses it by about 20-25mm, the weight of the floor panel should compress the insulation enough so that the floor panel touches the joists and is NOT supported by the insulation so much that the panel doesn't rest on the joist tops. then the total of rockwool is 10cm and total of studs plus neoprene is 10 cm and when the neoprene goes 20% down, the rockwool will push against the boards and there will be no ringing.. what do you think? or shoudl i find like 5x7 studs for more compresion of the rockwool? i will put one layer of the 18 mm (1.8 cm) chipboard in the live room and dead room.. (to expensive for 2 layers..) maybe i can put a layer of laminate some day later Will this floor also be floated, or is that directly on the macadam? but i have enough particle boards to cover the CR.. should i do a 2 layer floor in the CR.. first layer particle board and second chipboard ? i think the particle board is 20 mm.. but i am not sure.. what do you think? Yes, the heavier the floor leaf the better the isolation. I don't think you want to save material here, it needs to be right. one more thing.. if my walls will stand on the floated floor edges.. should i put more neoprene strips around the edge of the floated floor or should i put them evenly troughout the floor? You will need the pucks spaced closer under the walls because of the extra weight. Also, do you have a way to actually TEST the compression of the neoprene you have available? I describe such a test on page one of the floating floor thread you mentioned earlier, please re-read it and post back if you don't fully understand. One thing you need to remember, is that you're using different thickness of timber for your framing than I'm used to - so the same thickness of neoprene will give MORE support (less compression) under your joists than normal. This means that you will have to do YOUR OWN tests to find out how big an area of rubber it takes vs. how many pounds?kg) of weight. If you have an ordinary bathroom scale we can probably figure out a way to calculate things right... Steve

hey.. thank you for the reply.. all the floors will be floated.. live room cr and dead room.. :) the problem with insulation is that i have 10cm and the next one is 14 cm... so it is easier to find some narower joists :) i understand the calculating and doing the test for the neoprene.. :) you didn't say if my rockwool can rest on the asphalt... and maybe i can find more particle boards cheap..so if i do one layer particle and one layer chipboard that will not post a problem? how do i fasten the chipboard and particle board to the joists?.. same as the gypsum pannels to the walls? (screws at different centers?) and i dont understand the bathorrom scale thing :) i will do the calculations this afternoon :) so i will post something as soon as have it! thanks

Yes, the rockwool can rest on the asphalt - I would not, however, put any OTHER vapor barrier in the floor - instead, I would do whatever you can to leave air circulation under/around the floated floor, as long as it doesn't hurt your double envelope construction and keep it from having two continuous masses with air space/insulation between them. The asphalt will act as a vapor barrier, which (unfortunately) should be toward the INSIDE of the room instead of on the OTHER side of the insulation. All I can think to do for this is to let the floor BREATHE as much as possible, but WITHOUT violating any of the sound proofing rules you already know of. One layer of particle board and one of chip board will be fine; if you can get construction adhesive, I would use that on the FIRST layer ONLY - you want a solid connection to the joists, and make sure the screws sink at least even with the surface of the boards, so the second layer won't have any "lumps" to keep it from laying perfectly FLAT against the first layer. Stagger ALL seams, caulk all cracks before adding the second layer, and the same for whatever flooring you use over the top layer. The bathroom scale was just to weigh your joists, etc, because I don't have proper weights of the dimensioned lumber you're using. You need to know the weight of EVERYTHING that will be floated on those pucks in order to get the compression right... Steve

..hey. i made the test.. my neoprene compresses about 20% if i put 5kg or 11LB on 1 sq inch.. :) so now i can estimate.. :) i will measure the weight of 1m stud, one gypsum board, one chipboard, one particle board, one bag of insulation.... and then i will know how much strips to put :) one more thing with the compresion of rockwool.. it is very very rigid.. i cant compres it 20-25mm it goes max 5-10 mm. (when there is a big surface) .. i can push it all the way with my foot but i cant push it when i stand on the particleboard.. so i think my combination of 5x8 plus 2 cm neoprene will be perfect.. my 10 cm rockwool will compres 20% as the neoprene.. :) i hope it works out..! :) i will make some more measures tonight.. and calculate everthing :) one more thing.. what should i take in account when estimating the total weight.. all the permanent things inside? chairs tables building material.. or people and equipment (temporary) as well??

hey.. here are the newest measurments.. they are almost exact.. :-) i used this home thing.. that you measure when you are in the bathroom :) particle board 1 sq meter - 15 kg rockwool (for the floor) that i have (100x60 cm) - 3kg Wood door i have - 30 kg glass door i got for the CR - 53 kg (i got 4 of those for the 2 double doors in the CR) wooden stud 5x8 4m long - 8 kg gypsum board (200x125 cm) - 32kg metal stud (5x10) 4 m long - 4 kg iso glas for CR window - 17 kg mineral fibre (for the walls) 750x62,5 cm - 5 kg the chipboard is missing. i will have it tomorrow.. what about nails and other stuff?? is that incremental? should i include it in the calculation? here are the room dimensions (not totaly exact. maybe a few cm off) (in the next thread)

here is my calculation :) i it is all togeather about 76 sq meters is it ok if i just calculate how much stuff i put on on sq meter and just multiply it with the room surface? Petar

Petar, for the basic room itself you need to find out (weigh) what each type and size of building material that will be supported by your neoprene weighs, keep a running total, then divide by the # of square meters that particular floor covers, to get the weight per square meter that will be supported by the pucks. Then, you need to find out how much weight per square centimeter it takes to compress your rubber by 10% of its thickness - Then, you need to find from that, what your TOTAL contact area needs to be between floor joists and neoprene, and divide that out to find out how large each puck needs to be at acceptable span distances - if you're using those heavy 5x10 cm joists, the bearing area of the joist will be 5 cm in one direction and maybe 2.5 cm in the other, if you make the pucks 2.5 cm wide - they should be longer than it takes to go across the joist, maybe 75-80mm so they stick out past the sides of the joists a bit - they should be glued in place on the joists with contact cement. If you start by calculating the weight of ALL your building materials for each room, I'll help you work out spacing of the pucks - but you also need to experiment to see how much weight it takes to compress one of your double thickness (12mm total) neoprene pucks when that puck is 25mm x 75mm, placed CROSS-wise of one of your joists - Read the Floating Floor "sticky" first page, and then I'll explain anything that isn't clear... Steve

hi.. here a few more questions.. where can i find infos for soffit mount walls? does that wall go on the floating floor? i will start building the floor on thursday.. here is what i can do.. i can go with first layer of 1/2" gypsum board and second layer 3/4" OSB board (that is chipboard i think).. and that will be my final layer.. then i have to layers on the floor.. is that ok? 2 layers of chipboard is to expensive right now.. and you said different densities is better :) how much does a normal sofft wall weigh? ..i will do my calculations.. and will have a total on thursday morning.. i am pretty sure i understand that part :) Petar p.s. but i need the answer quick if i can go with first layer gypsum and second layer (final) OSB board.. if that is a good solution than i will do that! one more thing.. we decoupled the wood framing.. :) now we have separate dead, separate live and separate control.. you have to hear it!!! no structure born noise.. ..you really have to slam the wooden stud to hear just a little little little sound in the other structure (i think that is trough the floor or something..

That's great about the decoupling; NOT so great about using gypsum in this way. You would be OK if you were going to use the gysum BETWEEN two layers of sheet goods, like between two chipboards or particle boards or plywood - but gypsum isn't real strong for "crush", so what will probably happen if you use gyp directly on joists with chipboard over, is that the weight will tend to "squeeze out" the gypsum from between the two layers of paper, leaving a sagging, squeaking floor. If you can't afford the extra chip board right now, you would be better off putting just ONE layer of chipboard and adding a second layer later on. I'll be catching EVERYONE up this evening, including more info on soffits - need to go to my steel supplier before they close, so I can get some welding done tonite... Steve

hi, here one more thing before you answer.. i bought a lot of rockwool today.. they had a sale for 35% off (i got on sq meter for 2.5 dollars) .. and i got like 10cm thick but different kg/m3.. some is middle, some is very rigid, some very fluffy.. here the midle one 100x60x10 weighs between 3-4 kg.. that means 56kg/m3? divide by 16 is 3,6 PCF?? some is even more heavy like really rigid.. and the fluffy one is 100x50x10 is about 2 kg.. that means 40kg/m, that is 2.5 PCF Here some pics: i got 235 sq meters :) Some of the wool has this layer on them.. (the 3,6 pcf wool) you can see trough it.. that means it is like this cloth you can blow trough it.. but it protects you from the particles in the rockwool.. would this wool be good for acoustic treatment.. ? like the ceeling in the live room? and this layer on the bottom side.. so the particles dont fall down on you when it vibrates? tell me on which side to put this black layer.. facing the gypsum board or the room.. and one more thing.. i got this mineral wool.. with a some other layer on it. here how it looks like.. this was originaly ment for the live room ceeling.. should this layer be pressed on the gypsum boards or should it face the room.. you said i have to press the wool in the ceeling on the gypsum boards so they dont vibrate here the beuaty of decoupling: between live room and dead room live room and control room, 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.. i have a lot of cloths like this one: they feel like felt.. you can blow trough them but you have to blow really hard to feel something on the other side.. i have a lot of those.. should i use them somewhere?? i returned the wooden doors all except one.. that one i will use for the live room.. but for the control room i got 4 balcony doors.. sealed all arround.. have twice the mass as the wooden doors.. i think they will be much better :) and i will be able to see the people in the dead room now i got the 50$ cheaper then the wooden ones.. hehe the Floating floor.. should i use the more rigid one 3.6 pcf or the 2.5 pcf for the floor? i tested the 3.6 pcf and if i put the pucks to compress 20% it is so compresed that the board is not floating on the wool and the pucks are compresed.. here the test pucks and the wool.. (in the test i there was a board over it and i was standing on it) if i use the 2.5.. maybe i should put the 5x8cm joists so the i have 2cm puck, 5cm joists, with total of 7 cm.. and the 2.5pcf 10 cm which would then compres more... tell me what to do.. 2.5 pcf or 3.6,, and where to use the 3.6 here is the 2 cm neoprene rubber i will use to make the pucks.. the chipboard with folded ends it is like the laminate. i can put one chipboard in the other.. so there is no hole inbetween and so i don't have to seal it :) the joists.. 5x8.. i can use them verticaly.. 8cm high (with 3.6 pcf) or 5 cm high with the fluffy wool.. hope you can answer soon :) Summ the questions: what is the 3.6pcf good for? what is the 2.5pcf goof for? what to do with the layers on the wool (the black and the aluminiumlike)? wool in the floor which pcf? comment the doors and the chipboard :) should the rubber compress 10% or 20% one time you say 20 on time 10.. i am confused :) Petar