Caulk, sealer, mastic, silicone, etc....?

[qiktune]

Guys, I'm currently (still) building my studio and am really confused by all of the tubes on the shelf at Bunnings.

Firstly, in order to seal my wall and ceiling edges (2x layers 16mm) to each other as well as some framework corners I need some kind of "caulk". Obviously nothing on the shelves at Bunnings contains the word "acoustic" so am I correct in assuming that I'm really just looking for any type flexible/non hardening stuff? The price range is huge but doesn't seem to necessarily dictate that the more expensive will be better for my purpose.

Second, how many here have built studios with multiple layers of gyprock and had some success with a membrane other than Green Glue?

I'm really in need of specific brand names/product names so I don't end up wasting money.

Thanks guys,

Brett

[The Tasmanian]

As far as the joins:
Avoid any "gap sealer" as they dry too firm.
Silicon is the way to go as it stays flexible
Bostich brand is good for cheaper silicon sealant - bunnings used to have these for $2.50 a tube.
Any cheap silicon based sealer is good.

[stosostu]

Fuller Firesound is the best but it is expensive, and not many places stock it. There is a fully documented set of acoustic ratings tests on their website www.hbfuller.com.

If anyone has any personal experience or reliable acoustic data on a cheaper alternative I'd love to hear about it.

[The Tasmanian]

IMO there is no need to spend big $ on caulking gaps in corners - all you want is for the seal to have some flex and not dry out (ie silicon is best - no "gap filler").

There are so many things in a studio build that you cannot skimp on -
but here: why pay $17 vs $2.50 - you will end up using boxes of the stuff.
I am 100% sure you will find the whole process of building and wiring a studio will go way over budget by the time you have completed and opened your doors.

Its a very expensive process, and even if you have done it many times before and learnt all the tips one will always go over budget. (I've built well over 12 pro studios)
I don't know of any proper studio build in history that has not gone over budget.
You also wont pull many clients because of your class A sealant in the corners.
Good luck

[GlennS]

On the other hand, your studio is in your house, next to your neighbours & where your family lives. Do it right & do it once, I say. Some silicone sealers are crap, and I'm just talking about using it in my kitchen. If you're buying at Bunnings I think the one you probably want is Sikaflex Pro. In my last studio I used a variety of silicones & that was the best one.

[graemeh]

I've actually had good results with Selleys "no more gaps". After nearly 10 years I can still make an indentation with my thumbnail, so it's firm but not hard and rigid - it also stays fairly soft in the tube - I seal it with a nail. I just used some after it had been sitting in the caulking gun for 2 years - the first 50 mm was brown with rust from the nail but the remainder was perfect. So zero wastage!
But good quality silicone would obviously do a better job if there's any significant movement in the structure - in my case I used 5 cases of NMG and nothing's ever moved enough to open up any gaps or even cracks. I guess if your physical environment ie the land your building sits on is prone to movement, use silicone.

[qiktune]

Thanks for the input and ideas guys...very much appreciated.

I guess the product I choose will have to be in part be based on my environment. Although I don't mix at very loud levels, my neighbours bedroom is approx 5 metres from my mix position. On my side I'll have 2x layers of 16mm Fyrcheck as well as existing brick wall for mass - these are decoupled from each other with 50mm air gap and of course insulation in the cavity.

I've contacted Fuller for a price as their site doesn't list it ( hate that! ) and so far it looks like the product to use instead of GG between the gyprock layers.

I've also found a fairly cheap price on the Sikaflex Pro http://www.buildingsupplies.com.au/index.php?route=product/product&product_id=54 the sausage looks great value compared to what most outlets are selling the tube for ( $14 - $17 each ).

I reckon if I do a bit more "dry sailing" with a coffee in hand today that I could probably work out where to use what as far as sealants and the spend accordingly. I know my clients don't care how much I spent on the stuff but my neighbours will. I once had a band rehearsal here at 11:30am on a Saturday morning only to have the police show up and advise that there have been complaints. Apparently no matter what time of day or night, if someone finds the volume offensive they can make a complaint. I've been tempted so many times to complain about those obnoxious leaf blower things that drive me nuts.....pick up a friggin broom I say - I've even named my studio after the Monkees' song "Pleasant Valley Sunday"...cos that's where I live

[The Tasmanian]

If you spend $17 on a gap sealer, to do the job you mention then you have been fooled by marketing.
-and all of the studio building experts that have read lots of forums and have very little real building experience.
To expect any caulking to stop a band rehearsing at night leaking sound 5m from another dwelling is insanity.
You could build a 1 foot thick concrete wall and still have sound leakage problems.
Go forth and spend big

[stosostu]

I'm afraid Chris is right, no sealer is going to stop band noise in the environment you describe. Sound, especially low frequency WILL NOT be stopped, it can only be attenuated. If you consider that an acceptable leakage into your neighbours bedroom is, lets say, 40 dB and your band is playing at, lets say, 100dB (not a very loud band), then you have 5 metres to stop 60dB, and that doesn't take into account flanking noise. To achieve that you would need something like two isolated besser block walls, preferably sand filled. Mass is what attenuates sound, especially low frequencies, so the more mass the better. Then of course you will have to do something to stop leakage through the ceiling, windows, doors........... What you are asking for is not really practical and any serious attempt to achieve it would be expensive.

BTW Fullers Firestop is not a substitute for Green Glue. Green Glue is a specific product designed to go between layers of gyprock to provide increased attenuation, Firestop is a caulking compound with acoustic properties to match the gyprock.

[qiktune]

Ummm, yeh ok.

What does a band rehearsing at night and sand filled besser blocks have to do with my questions about specific caulks and GG alternatives?

There are no bands rehearsing here. I mentioned one instance of my own band doing a rehearsal at almost midday on a Saturday and Mr Jones down the road calls the cops. In the room I'm using presently I can mix all day and all night without the neighbours hearing a peep. One would then assume that by moving to a room specifically designed for it ( brick>insulation>cavity>insulation>2xlayers 16mm gyprock ) that the isolation would increase, yes?

Chris, based on what you said it'd be pointless for me to use any of the caulks suggested to seal the corners where gyprock sheets meet including floor and ceiling?

[The Tasmanian]

Brett why would you think that?
All you need is a flexible caulk that air seals the join - but does not dry out and crack.
You can use really expensive stuff - or a cheaper product that will do the job 100%.
I'm only trying to help out here and inform you as I am a carpenter/joiner/builder by trade - and I have built, designed and soundproofed many a recording and rehearsal studio - including in residential situations.

You put forward the band rehearsal situation - and did not imply that it was a one off.
Only trying to help
Also - attempting to save you some bucks.

[qiktune]

Thanks Chris, apologies for being a dick.

[GlennS]

Just be aware that sometimes they (i.e. Mitre 10) put silicone on sale when it is about to go out of date & is next to impossible to apply. I got caught out with that once. The reason I liked Sikaflex Pro was because it was really gooey & held really well when applying it to wider gaps.

[Bart Nettle]

Silicon can't be painted. Paint does not like to adhere to it.
An excellent product that drys more flexible than silicon is polyurethane. Perfect for double glazing etc. It is grey and very messy if you get it on your hands, it'll have to wear off. It is paintable.
"Bunnings "were selling it as "paintable sealant" I think by bostic.Not every store was carrying it when I was looking for some. About $8 .Actually when I was doing the job $5.50. Last time I bought some $8.
There are other brands that make the poly but it is more expensive. Sikaflex do one too and in colours. Pricey.
There is also a big sausage polyurethane from Roofing suppliers, but the guns for them are like $80. I think Bunnings carry them as well.

I used the poly between MDF door layers.

It would be perfect for plasterboard layers and while I have not seen green glue in person, I imagine it has similar properties.

You could knife the stuff with a stiff scraper and spread it all over. It is more viscous then silicon but will still need to be evenly spread.Do both sides that are to be joined rather than only one side if possible, but not as crucial as evenly spread.
When you start to lay the second sheet on if you have some help just lightly touch and lift off repeatedly to fluff up the stuff so that it is not so compressed in the sandwich as you put your temp screw fixings in to hold, while it cures.
What your trying to do is get some air bubbles within the poly itself and a slightly thicker gap. It'll be hard work but worth it. (Actually I just realised that plasterboard will probably break if you try to fluff it with it. Perhaps the scraper can be used to fluff it up.)


Totally recommended as better than silicon and never dries out. Like silicon it smells a bit as it cures. Do not use window silicon if you decide on a silicon. It stinks and dries harder than general purpose silicon.

[Junction]

Brett, it's kinda difficult for anyone to give you the ideal answer, not fully knowing the circumstance, i.e. how large, wide and deep is the gap. Fundamentally (as I am sure you know) sound isolation is only as good as the weakest link, i.e. you might have 32mm of gypsum board and a single bead of silicon of say 5mm diameter across a 5mm gap between the gypsum boards, so obviosuly 5mm of silicon is not going to perform as well as 32mm of gypsum.

I typically fill larger gaps with plaster to the full thickness of the board, which should then maintain similar charactersistics to the gypsum board and then a thin layer silicone over the joins on each side if you can get to them. There could be many techniques just depends on your actual situation.

I have also had "no more gaps in situations" for many years without any cracking, probably depends an whether there is any likely movement. No real easy answer, but just try to make it air tight and eliminate any isolating weak points in your total structure, paying particular attention to windows, doors, ceilings etc

A good reference site if you haven't already been there.
http://www.johnlsayers.com/phpBB2/index.php


Cheers

[The Tasmanian]

One more tip from me:
Stagger the joins on the sheets so that each gap in the corner overlaps the other - if you know what I mean?
this way the joint with the gap sealer is in different spot on the 2nd layer - better soundproofing.

[qiktune]

Gentlemen, thank you for the tips and input. So, as far as the frame joints ( and bottom wall plate to floor ) go I'm basically chasing a non-hardening caulk/sealant. Any gaps AFTER sheeting will likely be done with plaster as suggested.

I'll weigh up the costs etc of what's required between the sheets as a GG alternative as I read on the Sayers site that one option is to actually use three layers of 16mm and not using any GG at all. But for now, I'm finishing up the framework hence the question about sealing it.

I'll attach a pic of the layout so you fine gents have an idea of what I'm doing.

Thanks again guys, I do appreciate the help.

[Junction]

Hi Brett, it looks great. A bit hard to see the detail, but looks like you are building each room as a free standing box, which is good for isolation, but it looks like on the rectangular room on the bottom left of the drawing, you have bridged the gap to the adjacent room, just where the 0.42m dimension is. Can't see whether there are any other gap bridges .... but it's something you might want to look at/consider further.
Are you also doing the ceilings, consistent with materials in the wall construction?

Cheers

[qiktune]

That area you pointed out is actually decoupled, it just looks attached in sketchup. The new frame goes under a pre-existing load bearing wall frame.

The wall frames are constructed with Rondo stud and track and the new ceiling will be done with timber joists sitting on top of the inner wall frames so it too will be decoupled from the existing structure.

[mrtuesday]

Yep - Polyurethane sealant is the way to go.
This is what I used - Bostik Seal N Flex 1 Polyurethane Sealant (http://www.bostik.com.au/construction-t ... 0-g-0.html).
Can usually get it from Bunnings & cheaper than others - I used HEAPS of it. Seal everything, everywhere!

For my ceilings I used a product called Barrierboard from http://www.totalnoisecontrol.com.au/.
Basically 2 sheets of plasterboard with a layer in between. Meant to be more effective than plasterboard/green glue & quicker to install (damn heavy though - that was a fun day putting it on the ceiling!)

Instead of green glue I used a product called Quietwave (http://noisescreen.com.au/quietwave.html) in a couple of doors. A kind of recycled rubber meant to do similar thing to green glue but just cut to size.

Good luck!

[rick]

i have been sitting this out to see what i could learn

what you want and need and can get easily locally is fuller firesound
its pretty cheap
track down a stud n track type place and by it by the box or tub

i can think of two dozen reasons to argue the point with lots of suggestions given
but mostly they are suggested because the correct product was not easily found, known
deemed too expensive or from previous users history others seemed to have worked out ok


when i finally found firesound after two decades of looking building and wondering and testing
i knew the search was over
i have done LOTS of personal un csiro type testing in the last year

silcon and polyurethane bunnings types is NOT what you want and you will never know

because you can never know after the fact

fire sound is about 5 bucks a tube if you buy a case
and if you buy it buy the bucket even cheaper !

oh yes as you may guess by the name it is DESIGNED for the exact job
what more do you want from it .. ?

[qiktune]

Ok so I'm off to Meadowbank to pick up some Firesound. The cheapest I can get the cartridges for is $7.50 each ( $90 per box ) and $135 for the 10L bucket. Perhaps my haggling/negotiating skills like everything else need some work.

I did try a few places more local to me ( Camden area ) but no luck and the one guy who I spent some time on the phone with really pushed the Sikaflex Pro as the best alternative. I don't mean "pushing" in a bad way, he was great it's just that at $17 a cartridge, well....

Since you guys have all been so amazingly helpful to me I wonder if you can help me with the other question I have re insulation. I asked over at the Sayers site but things tend to get lost in translation since there are different products globally with either the same "name" or reffered to in the same way.

Filling up my wall and ceiling cavities with "pink fluffy stuff" is suggested but it seems that the pink fluffy stuff in Oz has a too low nominal density eg, Fletchers Pink Batts which are 8-10kg/m3. I've made a lot of enquiries but can't seem to find anything around the suggested 25kg/m3....beyond that it's Soundscreen which is 38kg/m3 and apparently too dense for a MSM construction. The idea being that I should use Glasswool for the exterior of the room and Rockwool for interior treatments.

Sometimes I just get so confused and think "hell with it" I'll just use the pink ( or yellow ) stuff that's all over ebay at the moment and completely fill the cavity with it rather than just placing it between the studs. Have any of you guys thought the same when building your rooms? Just get what is available and affordable and double up the materials that are cheaper...eg, lighter insulation in conjunction with an extra layer of gyprock.

[qiktune]

I should actually add here what my understanding is re the purpose of insulation in studio walls. It is there to dampen, correct? The gyprock/brick walls are acting as mass ( to try to stop sound escaping/entering ) and the sole reason for insulation is to dampen/diffuse the frequencies/sounds that can't be constrained.

[waitup]

I should actually add here what my understanding is re the purpose of insulation in studio walls. It is there to dampen, correct? The gyprock/brick walls are acting as mass ( to try to stop sound escaping/entering ) and the sole reason for insulation is to dampen/diffuse the frequencies/sounds that can't be constrained.

I might be wrong, but I'm under the impression that insulation is added to the wall structure (between studs) to add mass and to dampen the wall, which can potentially resonate, is it is a membrane.

[Junction]

Whats pink fluffy stuff? .... sounds like fairy floss. Not an expert on the science, but everything I have read from experts suggests that you should'nt stuff the cavity full with you fluffy stuff, you are better to use more dense material like rockwool and only partially or half fill the cavity and leave some air space, where I think the air cavity mixed with other materials like rockwool and gyprock etc enhances the attenuation performance.

[GlennS]

Fletcher make Sonobatts which are glass wool & start at 22kg/m3. Tontine Acoustisorb1 is also 22kg/m3 & is a great product, not glass wool though & perhaps a bit pricey.

I had read the opposite to Michael, that filling the airspace with regular insulation is better than leaving it empty. Perhaps I had just read that on the Sayers forum, I can't remember.

Brett, do you have that "Build it Like the Pros" book?

[qiktune]

Re what's pink fluffy stuff? Exactly! I understand the fundamentals and science remains the same as far as building the studio goes but it seems that the approach and materials used is forever changing and can become quite confusing. The thinking now is to not use Rockwool in the cavity as a less dense insulation that breathes more easily also makes for a better "spring" in a Mass-Spring-Mass construction.

I'm out grabbing the Firesound now and typing VIA my phone. Will check in once home.

[Junction]

.... and there is the reason why some spend a lifetime studying acoustics, because some less qualified think there should be an air gap, others think not, some think we should use dense rockwool, other think the pink fluffy stuff is the way to go.
Now suitably confused.
Brett when you work it out, let us know please

[qiktune]

I should actually add here what my understanding is re the purpose of insulation in studio walls. It is there to dampen, correct? The gyprock/brick walls are acting as mass ( to try to stop sound escaping/entering ) and the sole reason for insulation is to dampen/diffuse the frequencies/sounds that can't be constrained.

I might be wrong, but I'm under the impression that insulation is added to the wall structure (between studs) to add mass and to dampen the wall, which can potentially resonate, is it is a membrane.

That's what I thought too...

you are better to use more dense material like rockwool and only partially or half fill the cavity and leave some air space, where I think the air cavity mixed with other materials like rockwool and gyprock etc enhances the attenuation performance.

Yep...

Fletcher make Sonobatts which are glass wool & start at 22kg/m3. Tontine Acoustisorb1 is also 22kg/m3 & is a great product, not glass wool though & perhaps a bit pricey.

Thanks Glenn, Tontine was the very first product I checked and would have liked to use it but it is indeed a bit pricey. I'll check with Fletchers and see what they can do on the Sonobatt

I had read the opposite to Michael, that filling the airspace with regular insulation is better than leaving it empty. Perhaps I had just read that on the Sayers forum, I can't remember.

Brett, do you have that "Build it Like the Pros" book?

That's exactly what I'm reading on the Sayers forum now...a bit confused. I do have that book Glenn and after announcing to my dad that I think my copy was printed in Chinese he took it in order to translate it for me. I'll have to grab it back when I'm next over there.

[stosostu]

Unfortunately, acoustics is a highly technical subject and you really need at least a basic understanding of it before you start a project like yours. You just cannot 'guess' what material to use or how to use it, and you can't just do what someone else did unless your requirements are identical. You can use the same materials in different ways to achieve a wide variety of results. In fact you can actually make things worse by using the correct materials in the wrong way. You should have a look at Rod Gervais' book and also Alton Everest's book (a free download is available here, http://www.filestube.com/6cb2f64d49c4d4 ... stics.html) before you begin, then use your knowledge to design a solution that is appropriate to your needs and budget. Quite reasonable reasults can be achieved at acceptable cost if the right material is used in the right places. But if you just steam in unprepared you may find that you've spent a lot of money for no improvement or even worse, then you have to pull it all down, do the reading and start again.