Plastering studio walls vs acoustic caulk

J

jmchug

New member
Hi

The builder who is building my garden home studio is nearing the finishing stages.

He has built a decoupled inner room which has includes two layers of 12.5mm fire board green glued together.

I expected him to use acoustic caulk to seal the joins and screw heads on the inner layer of board but he has instead taped up the joins and is about to plaster the walls and ceiling - which will then receive three coats of paint. He says doing this negates the need to use acoustic caulk on the joins.

What do you think?

John
 
I think I see your point but do you think sound is going to come through the tape, filler and plaster? I should imagine the 2 layers of plasterboards have staggered joints so there isnt a direct link from one side to the other?
 
Orson said:
I think I see your point but do you think sound is going to come through the tape, filler and plaster? I should imagine the 2 layers of plasterboards have staggered joints so there isnt a direct link from one side to the other?
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Hi Orson

He's used acoustic caulk between the joins on the first layer of fireboard. Then yes he has staggered the joins on the second layer but hasn't caulked these joins. He's just taped them and now it's been plastered all over. I intended him to caulk the joins (not just tape them) on the second layer, but he says plastering it all will absolutely do the job.
 
yes plastering over it will seal it all up properly, but any gaps do need to be sealed before hand, if the first layer is definitely well sealed it shouldn't be a problem.
 
In the ones I've built myself, staggered joints work fine, and the various types of caulk seem to have minor differences. In essence, the density of the product in just higher in one than another. The simple test is to borrow a disco smoke machine and fill the room up with thick dense smoke, then wait to see if you can spot it escaping. There will probably be far worse unexpected paths to the outside world than these corner joints. Doors, windows and where the ceiling fits will be the worse points. Mine always have been.
 
rob aylestone said:
In the ones I've built myself, staggered joints work fine, and the various types of caulk seem to have minor differences. In essence, the density of the product in just higher in one than another. The simple test is to borrow a disco smoke machine and fill the room up with thick dense smoke, then wait to see if you can spot it escaping. There will probably be far worse unexpected paths to the outside world than these corner joints. Doors, windows and where the ceiling fits will be the worse points. Mine always have been.
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that's a cool idea rob, might have to use that to test out my room.
 
I wouldnt think you have a problem. From the plasterers point of view he is trying to do his job correctly. I dont think you will see smoke.
 
The weak link for me has always been getting a good seal where walls meet the ceiling, as my walls are not parallel, which means lots of angles on the ceiling panels, and they were too easy to create paths. I solved this one on the last build where I laid the first plasterboard on top of the wall top plates, then sat the ceiling joists on top, and screwed them through the plasterboard - so the first layer perfectly sealed then the other layers are 'safe'! I'll do this again.
 
First time I've ever heard of acoustic caulk - can someone explain what makes it different from other forms of caulk?
 
I think it's a bit snake oily, not sure if there's any real evidence of genuine improvements, you can use normal caulk, the key is that's its well sealed.
 
Has anyone ever built a studio, measured it's capabilities, then re-built it using all the little tips and tricks? That's the trouble. Sometimes, like with windows - you can add an extra pane, and discover very little happened, but as for staggered joins, and different caulk types, I bet that the big hole you put in the wall to let air in and out spoils things much more.
 
I built mine. It is a large timber construction with walls insulated with 10" of normal loft insulation. Then I put up the interior walls and ceiling of 18mm osb/plywood. It wasn't too bad there was a reverb. But not very much. It was ok and could have been easily treated. I read that you need to put plasterboard/sheetrock walls and ceiling in to absorb the sound. So I did at great expense persuaded by the fact I could easily paint these walls, which I couldn't do with osb board and a type of yellowy orange isn't my favourite colour

After lots of work and cash later I had turned my studio into an echo chamber. Shouldn't believe all the crap you read online.
 
Orson said:
Could you explain?
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Thick or heavy walls, doubly insulated, etc. are steps folks take to prevent sound from moving through walls, both in or out, i.e., sound proofing. This is absolutely necessary for a professional studio, for instance, where you have to be able to record on schedule, and can't say "Come back after the lawn guy is done outside."

Room treatment is what you do to make an inside space sound better and have "good" acoustic properties, e.g., for recording or mixing. It's also critical for professional studios, and, of course, most of us home recorders (sooner or later) recognize the importance of it for both mixing and recording. It eliminates those echoes that intrude in recordings, consumes bass frequencies that can build up and distort your hearing of the mix, i.e, by introducing room sounds into what you believe is just the recorded tracks.

Home recorders really should worry about room treatment. Whether you have to do sound proofing depends on what you really want to do, how flexible your schedule is, how large, reconfigurable, or re-buildable your space is, what your budget is, etc. For me, when the lawn service is next door or it's the weekend and the hobby pilots are buzzing the neighborhood, I simply say "take 2" or decide maybe the next day is going to work out better. I don't even contemplate soundproofing, save minor seals around the big gaps like windows and doors. But I've done a lot of room treatment, with acoustic panels and bass traps so I can both record and mix without the room being too intrusive. As a hobbyist home recorder, as well as someone who's been married a long time to the same person ;), I know my limits...
 
Ahh I see I understand and this is my fault.

The building was originally for another purpose and I blocked up the 4 windows so now it has none. The wall insulation was for heat purposes and I added another 2" of acoustic insulation onto it making it 10" in total.

I then put osb board on the walls as it is a much better job than plasterboard and because I purchased a full bail (50) I put them on the ceiling as well. All was ok until I did a video inside and it was affecting the light (yellow/orange). You can't really paint osb as it would suck it up and require lots more than usual. Acoustically it wasn't too bad as I believe the wood/osb absorbs sound to an extent.

I then read about plasterboard being required for soundproofing so I thought adding to soundproofing and being able to paint.....kill two birds with one stone.

Nobody says anywhere I read that plasterboard is extremely bad acoustically and requires lots more acoustic treatment than osb board............so it is actually going to cost me even more money than just the extra it would have cost to paint the osb.:mad:

You live and learn.
 
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There's a young guy on youtube called Alex Steele, who is a blacksmith and he just moved from the UK to Montana. In his first videos from the new shop, the blockwork walls and concrete floor made the acoustics bad for speech - but of course he will be hitting hammers, and making lots of noise, so his first job was timber frames with rock wool, covered with, in his case, flags. If you listen to the very reverberative sound, then how just a few square yards of rock wool on the walls makes a difference, it's pretty drastic.
 
Orson said:
Ahh I see I understand and this is my fault.

The building was originally for another purpose and I blocked up the 4 windows so now it has none. The wall insulation was for heat purposes and I added another 2" of acoustic insulation onto it making it 10" in total.

I then put osb board on the walls as it is a much better job than plasterboard and because I purchased a full bail (50) I put them on the ceiling as well. All was ok until I did a video inside and it was affecting the light (yellow/orange). You can't really paint osb as it would suck it up and require lots more than usual. Acoustically it wasn't too bad as I believe the wood/osb absorbs sound to an extent.

I then read about plasterboard being required for soundproofing so I thought adding to soundproofing and being able to paint.....kill two birds with one stone.

Nobody says anywhere I read that plasterboard is extremely bad acoustically and requires lots more acoustic treatment than osb board............so it is actually going to cost me even more money than just the extra it would have cost to paint the osb.:mad:

You live and learn.
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Ouch.
Was your initial focus then on isolation and a low internal noise floor? It seems you might have accomplished that.
I would expect either of those materials though, given similar non flexing constructions would have minor differences acoustically.
Trying to 'make the most of our (my.. :>) humble home limitations.. I look for the bright side of things. Like 'that big opening between the mix and record area..' Heck, that's a 'freebie ..breaking up my room modes.
:)
 
No I am a carpenter and having walls made of 12mm compacted powder (plasterboard) is in reality pretty useless if you want to hang or fix things to it. So buying a bale (50) of 18mm osb/ply would make the walls super strong and fix anything to them. Even better on ceilings as well. Ok worked out twice as expensive but a much better job and better acoustically........untill........:rolleyes:

As regards the insulation....yes I wanted as quiet as possible but also little heating required but then another problem of ventilation and moisture control.........so things can get quite complicated.
 
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