I'm so confused!!!! - Small room construction tips

Hey everyone, I'm new around here so be gentle! A wise sage once told me too much info is the same as a lack of knowledge but I thought... "meh, I need to do as much research as humanely possible before I spend my hard earned cash".... However after days and nights of hard toil, watering eyes from reading copious amounts of forums I've realised... maybe I'm wrong. Hard facts are; I've inherited a small space in London England, 15ft long, 9ft 4 wide, 9ft 8 from a 10 inch raised floor to the actual ceiling metric version reads, 4.57 metres long, 2.84 metres wide, 2.94 metres from 25cm raised floor to actual ceiling The ceiling is also dropped but I'm pretty sure I will remove it as build quality is poor and it is too low (8ft from raised floor). The unit on the 2nd floor of a large industrial building and at the moment sound is leaking and entering from the adjacent corridor and the corridor from the floor above. I want to be able to crank up my speakers in the day and not disturb the units in the vicinity + record vocals without being heard from outside the room. I'm confident I need to build a studwall-placing them on neoprene type isolators (for decoupling) with acoustic board and rock wool with an airgap to give good isolation as well as the same for the ceiling to create a room within a room, but I'm concerned about flanking and the floor construction. I'm getting conficting information- underneath the current raised floor (just rockwool, fibreboard and wood)The floor is solid feels like maybe concrete with tiles on top. some say rip out the current raised floor and build a joist type raised floor on uboats-others say u boats have no benefit and any floated floor construction is useless unless its precisely engineered and expensive. I say aahhhhh, I'm confused, what do I do? do I even need it? I have some pics if this helps any advice appreciated ps. a little side note: though the walls are solid brick there is part of one wall that looks like it was a doorway previously that has filled in with breeze block but still recessed a little as in not flush. Should I add in fluffy rockwool and board it up before constructing inner walls? Thanks Rob Basic plans listed below Remove existing ceiling and floor 1. Build stud walls away from existing walls - build all 4 walls for room within a room construction - place on studwall isolators 1200 x 90 x 6mm - fill with Rockwool RWA45 insulation - add 2 layers of acoustic plasterboard to inside face only - use green glue between layers of plasterboard - seal all joins and perimeters with acoustic sealant (seal layer 1 before adding layer 2) 2. Build ceiling on top of existing walls - like the new walls this ceiling should not touch the existing structure at all - fill with Rockwool RWA45 insulation - add 2 layers of acoustic plasterboard to inside face only - use green glue between layers of plasterboard - seal all joins and perimeters with acoustic sealant (seal layer 1 before adding layer 2) 3. Build raised floor - should sit inside of new walls with 10mm expansion gap all the way around - place on joist cradles every 400mm http://www.eqacoustics.com/products-pag ... -isolators - you can reuse your existing floor timber and insulation if you wish - use 2 layers of 18mm MDF with a layer of acoustic plasterboard between them - put green glue between the layers of board - seal all joins and perimeters with acoustic sealant (seal layer 1 before adding layer 2, 3 etc) a heavy door with acoustic seals

Hi there Rob "sumbody", and Welcome! :)

I need to do as much research as humanely possible

Naah, you got that part wrong: You need to do a LOT more research than that! :)

The unit on the 2nd floor of a large industrial building

You are probably already aware, but second-floor studios are a bit harder to isolate than ground floor, for several reasons.

I want to be able to crank up my speakers in the day and not disturb the units in the vicinity + record vocals without being heard from outside the room.

OK, so you are not planning to record anything extreme, like bass guitar or drums? If it is just vocals and mixing at normal levels, then you should be OK. Or at least, it is feasible to isolate the room to a decent level for vocals and mixing.

I'm confident I need to build a studwall-placing them on neoprene type isolators (for decoupling)

Not really. Or rather, yes, you do need to build the stud-framed walls, but no you do not need to use neoprene isolators to decouple the walls form the floor. In fact, it is impossible to do so, for a simple reason: Your walls MUST be attached to the floor somehow: nails, screws, bolts, etc. Whatever method you use means that there will be a solid, hard mechanical connection going through the sole plate and into the sub-floor, totally bypassing the neoprene. So the neoprene will not decouple anything. It might help to get a better air-tight seal under the wall, but it will not decouple, since the anchor bolts provide multiple direct flanking paths that bypass the rubber. So save yourself some money, and skip the rubber. That is not the way to float a wall, despite what some "expert" web sites try to tell you. Myth #1 busted.

I'm getting conficting information-

Yup. It happens frequently. On the internet, everyone is an expert! There are so many myths, lies, half-truths and snake-oil products out there that it just isn't funny. And there seems to be an army of ignorant folks that love to perpetuate those myths, based on no facts at all: just guesswork and repetition of "I read it on the internet, so it must be true..." ... :) So lets have a look at myth #2:

underneath the current raised floor (just rockwool, fibreboard and wood)The floor is solid feels like maybe concrete with tiles on top

Excellent! That is what you need for your floor. Perfect.

some say rip out the current raised floor

Exactly! That certainly is what you need to do. What you have now is a resonant cavity floor, also known as a "drum head". In acoustic terms, that floor is nothing more than a membrane stretched across a framework, over a resonant space. Exactly like a drum. And just like drums do, yours resonates (vibrates) at certain frequencies that are set by the mass of the floor (surface density), the depth of the cavity (distance between the underside of the wood and the top of the tiles), and the damping (rockwool). That is a major problem. That resonant system has to go, or you will never be able to get decent acoustics in the room. The floor needs to be solid, hard, massive, non-resonant. Such as concrete, tile, etc...

and build a joist type raised floor on uboats

Bad idea. That's the myth. The vast majority of studios do NOT need their floor floated. Floating a floor is serious business, and hard to do right.

others say u boats have no benefit and any floated floor construction is useless unless its precisely engineered and expensive.

Those are they guys telling you the truth. If you want the detailed truth, try reading through this thread: viewtopic.php?f=2&t=8173 These two might help as well: viewtopic.php?f=2&t=8134 viewtopic.php?t=8135 And if you want a technical analysis of what actually happens and why it is a bad idea, try this research paper: http://www.nrc-cnrc.gc.ca/obj/irc/doc/p ... /ir802.pdf Myth #2 busted. (I hope?) What you really need for your floor is that concrete or tiled concrete surface that is a few inches down. That is the ideal, perfect surface for a studio floor. And you will also gain several inches in height by ripping out the drum head that you have right now...

ps. a little side note: though the walls are solid brick there is part of one wall that looks like it was a doorway previously that has filled in with breeze block but still recessed a little as in not flush. Should I add in fluffy rockwool and board it up before constructing inner walls?

All of the brick surfaces around the room need to be sealed first, before you do anything else. A key part of isolating a room is to make it air-tight. Bricks and concrete are porous, and therefore need to be sealed. A coat or two of good quality paint should suffice. Another (even better) option is to stucco/plaster all of those walls completely: not only does that seal it, it also adds mass, which is a good thing. Mass is your new best friend. Yes, you will need insulation in the gap between your existing outer-leaf wall and the new inner-leaf wall that you need to build to isolate the room. But that is part of the isolation plan, and we'll get to that later.

- add 2 layers of acoustic plasterboard to inside face only

You do not need acoustic plasterboard: that stuff is expensive, and offers only slight advantages (if any) over ordinary fire-rated plasterboard. Sound waves are not fussy: they do not care how much you paid for the mass that stops them. They can't even read the price tags! All they do is react to the mass. So get the least expensive mass that will do the job. You do not need exotic materials, and there are no magical materials that can bypass the laws of physics. Sound waves follow the laws of physics, not the laws of magic or marketing hype, so it is best to use materials that stick to the laws of physics too.

- use green glue between layers of plasterboard

If you can afford it, and if you need high levels of isolation for low frequencies, then yes, that is a good idea. But it ain't cheap.

3. Build raised floor

Skip this step entirely, and save yourself a bundle. You almost certainly do not need a floating floor, and after having read the above info on the links I gave you, you should have a better understanding of why this is so. Plain old ordinary concrete (or tiled concrete) is a great acoustic surface. If you do not like the look of the tiles, or if they are in lousy condition, then consider laying laminate flooring directly over that, with no air gap. Ceiling: I would rip out the ceiling too, if that were my place. It is doing you no favours, and is taking up valuable space. Sound waves like space. Room height and room volume are very important for good sound, so take out as much as you can to give yourself the maximum sized outer-leaf envelope, before you do anything else. That will also give you the opportunity to inspect all those surfaces to see what you have there, and to repair/seal them. Sounds like you have good prospects for a nice studio here. Especially with all that extra space you will gain by ripping out the drum-head floor and ceiling! - Stuart -

Seems like I’ve found another wise sage! Stuart you just knocked my question out the park…home run! Awesome info :yahoo: , you are indeed a myth-busting maestro! Everything I wanted to know and it all makes perfect sense to me

Sound waves are not fussy: they do not care how much you paid for the mass that stops them. They can't even read the price tags!

So true! :lol: had my suspicions and in general I have been quite cynical of some “experts” whom I suspected to be sales people in disguise.

Naah, you got that part wrong: You need to do a LOT more research than that!

Seems as though construction will actually be the easy part! Though saying that, I need to find someone to actually put this together as I’m a health & safety hazard with any tool in my hand! The builder I have in mind is actually a carpenter, is there any specific advice, common pitfalls I should point out before he begins? E.g. how to align the studs, plasterboard seams etc.

Sounds like you have good prospects for a nice studio here. Especially with all that extra space you will gain by ripping out the drum-head floor and ceiling!

I think so too! Thank god for the internet though, could have been a disaster! Thanks Rob

Thanks for the kind words, Rob! Much appreciated. :thu:

The builder I have in mind is actually a carpenter, is there any specific advice, common pitfalls I should point out before he begins? E.g. how to align the studs, plasterboard seams etc.

Well, first, he'll have to forget everything he ever learned about construction techniques... :!: :shock: :D OK, so it's not quite that bad, but there are many things that he will need to do differently. Building a studio is not like building a house, office or shop. Same materials, same tools, different methods and techniques. Things that he is used to doing and never even gives a second thought normally, will now become critical. For example: airtight seals. He never needs to bother about that, but now for a studio, it is absolutely essential that he must seal every possible gap and crack. If air can get through a crack, then so can sound, so he needs to work with that in mind. Also, decoupling: Some parts of the studio will have to be built so that they do not touch other parts. Even one single badly placed nail that accidentally bridges what is supposed to be a decoupled gap, can ruin the isolation that you are fighting so hard to create. Also, materials: He might be tempted to substitute, but that could have serious consequences too. For example, he might not have any 2x4s on had at a certain point, and figure he can just use a 2x3 or 2x6 instead, since there are no structural issues. But their might be acoustical issues, so no substitutes are allowed. If the plan says 5/8" fire-rated drywall, then 1/2" ordinary drywall is NOT a valid substitute, and would greatly harm your isolation. Etc. So the basic issue is: can he follow instructions perfectly, and accurately?

Seems as though construction will actually be the easy part!

Oh yeah! A very wise forum member uses the following phrase as his signature: "Building a studio is 90% design, 10% construction", or something to that effect. He's spot on with that! If it is designed carefully, in full detail, with everything being fully thought through, then the actual construction will be a breeze. (Maybe...!) - Stuart -

Much appreciated once again, I will keep these in mind it's going to be interesting! Rob