2 Questions on the construction of new studio

I have a 2 layered concrete block space and I'm in the middle of designing the internal structure. The dimensions are 5m x 8m. Inside the 2 concrete layers of 4" block. This is what is planned. 4" gap. 4" stud partition, filled with rockwool. Then.... Either 2 sheets of standard 5/8" drywall with greenglue inbetween OR 2 sheets of acoustic slab-board, (BlueBoard I think is the proper name), without greenglue inbetween. The quote i got to get the greenglue shipped etc. to Ireland from England was €1500. This seemed very costly, so the question arose was it needed! If needed, that's fine, but if not, would the 2 sheets of BlueBoard costs a lot less. ****The double layer of drywall/blueboard with or without greeglue will also be used on the ceiling!**** The 2nd question Which is preferable in terms of acoustics and sound isolation, A PVC door OR Solid timber door for entry and exit. All help is appreciated!!! Donal

Hi Donal. welcome. Please check the forum rules for posting: You seem to be missing something... :) On the Green Glue question: You don't need it. An extra layer of drywall is about as effective as the GG, except perhaps in the very low end. So if an extra layer of drywall all around your room is cheaper than the case of GG, then do that. If the GG is cheaper, then do GG. But why do you say that you'd do drywall will GG or "acoustic slab-board" without it? I don't see the connection: Mass is mass, and sound waves don't care how much you paid for it. They only react to the mass, regardless of the price tag. So go with the cheapest form of high-density mass you can find. In most countries, that usually turns out to be plain old ordinary fire-rated drywall. So unless that "acoustic slab-board" has more mass for the dollar (higher kg/m3) than drywall, then forget it. There's a lot of products out there on the market that make claims about high levels of isolation, but the fact is that the laws of physics are not subject to magical incantations: Sound waves are stopped by mass, period. There's nothing you can do to mass to make it stop sound waves better, except to add more mass or use it in a tuned MSM system. There are no magical products in acoustics that somehow bypass the laws of physics. (Green Glue sounds magical, but isn't: it works on the principle of constrained layer damping, and it does work, but once again there's a cost/benefit thing here: is it cheaper to add enough mass to get the same effect as the crate of GG, or not?.)

would the 2 sheets of BlueBoard costs a lot less.

I don't know what "BlueBoard" is, but it's easy to figure out which product is better: How much does it cost per kilogram? That's the bottom line. The only time you might want to go with a more expensive product is if you are very tight on space and need to put the same amount of mass in a smaller volume, to save an inch or two of room width. In that case, you could go with something exotic like steel plate o lead sheeting, which are extremely high density, but just a tad more expensive... :)

Which is preferable in terms of acoustics and sound isolation, A PVC door OR Solid timber door for entry and exit.

Solid core wood is what you want. Once again, it's a simple matter of mass. If your door has lots of mass, it will attenuate sound well. If it doesn't, then it wont. There are no shortcuts, unfortunately! The key to good isolation is mass, mass and more mass, plus total airtight seals around both leaves of the room.

Inside the 2 concrete layers of 4" block. This is what is planned. 4" gap. 4" stud partition, filled with rockwool. Then.... 2 sheets of standard 5/8" drywall ...

I¿m not sure I understand: You say that the walls already consist of 2 layers of concrete block: Is there an air gap between those layers, or are they solidly tied together? If there is a decent air gap, then you already have a two-leaf wall. But you didn't mention the most important details of all: How loud are you? How quiet do you need to be? What type of music / instruments? Is this just a rehearsal space, just a control room, or a control room plus a live room? Or something else? What about the floor? What about the roof? All of that matters a lot in answering your questions intelligently! :) - Stuart -

But you didn't mention the most important details of all: How loud are you? How quiet do you need to be? What type of music / instruments? Is this just a rehearsal space, just a control room, or a control room plus a live room? Or something else? What about the floor? What about the roof?

Sorry Stuart, did the post quickly and obviously left out ALOT!! The live room will be used as a rehearsal space a lot. This is when the most sound will probably come from inside the studio with drums guitars keys etc. The hope is that eventually it will be used as a recording studio. The danger here is that there is a garage about 20 feet away, which can create a lot of noise with reving and such. So I need sound to be kept out, just as much as sound needs to be kept in. Yes, it will be a 2 roomed studio. The live-room being roughly 4.8m x 5m and the control room being 2.8m x 5m. The wall inbetween the 2 rooms is two 4" stud partitions stuffed with rockwool with a 5" air gap inbetween, with 2 layers of drywall on both outer sides. There's a hipped roof, consisting of concrete tiles then the huge air gap. The inner ceiling which will be 4"ceiling joists stuffed with rockwool, with 2 layers of standard drywall on the inside. The floor is just a solid concrete base, The height of the room is barely 8 foot, so floating the floor would decrease it even more. So i think i will just leave it as is, put a thin carpet down on it. The reason I was saying Standard Drywall with G.G ORThe BlueBoard without G.G, because to do Blueboard with G.G (which would supposedly be have the greatest Soundproofing ability) would cost too much! But if mass is mass, then I suppose it's just as effective to go an extra sheet of drywall! Thanks for clearing that up! The outer wall is sort of 2 leafed already, its 4" block with a small gap then the next 4" concrete block. What would you advise to do? Technically the inner structure will create 3 leafs, however the gap between the concrete layers is minimal! Thanks fr the reply, any other advise would be great! :) Donal.

Donal, Please update your profile to include you geographical location.