rehearsal space in existing tin shed

[neilstar]

Hi Steve,
the gg sealant is obviously different to the gg compound,
so do i use the sealant around the edges of the sheets of gyprock(fyrcheck) and any other joins and the compund just between the layers of gyrock(fyrcheck)
how does the compound between the sheets help with isolation,

have you used the sikaflex11FC for all your joins and any gaps, eg. holes in the walls air con, and small holes around electrical cables for power and lights

cheers Neil

[stevev]

do i use the sealant around the edges of the sheets of gyprock(fyrcheck) and any other joins

yep. the idea is that you're trying to make a room that will stop air from getting out. (hence the expensive air-con). So anywhere that air-molecules (very small) can possibly get out, then that's where you run some sealant. If you're doing a double layer of fyrcheck then the first layer that attaches to the wall studs/rafters will need to be sealed around their entire perimeter.

Also consider the bottem plates of your wall assembly where they meet the concrete and where your internal ceiling and walls will meet.

how does the compound between the sheets help with isolation

magic

But seriously, you'll have to look at the GG site for very detailed information. As far as I understand it, it acts as a damping layer between the two heavy and rigid sheets of plaster which effectivley combines them to be greater than the sum of their parts. And I can tell you that it works

have you used the sikaflex11FC for all your joins and any gaps, eg. holes in the walls air con, and small holes around electrical cables for power and lights

the sikaflex I use is 221 (black tube, like liquid rubber, incredibly expensive!!!) . I've only used it to seal around my aircon inlets as it deals with large gaps very well (and is expensive) it's a fantastic product that wll join and seal just about anything to anything else (did I mention how expensive it is )

All of my internal walls have been built inside-out so all the wiring etc is on the inside, which means the only penetrations are the mains cable and the air con. The mains cable is sealed with GG sealant as it's only a small hole and you know about the air-con.

You should be fine to use the GG sealant around small wiring holes etc as long as you keep the 'attention to detail' high.

[neilstar]

thanks again steve for your response, going to do some more research on pricing fyrcheck, insulation and green glue, then the installation process,

still not sure if filling the 300mm wall space with light insulation is an option considering im using 22mm ply and 2 layers of fyrcheck, or
i should definetly be putting a more dense insulation, or at least 1 layer is any benefit

cheers Neil

[neilstar]

gg compound is rather expensive, do you think using 1 28oz tube of the gg compound per 2400 x1200 is enough, i would need 24 tubes that still totals 24 tubes = $600

and then the gg sealant all around the edges and any little gaps


other question? do you have a seperate power cable for lights into your room or do you power lights and all equipment off the same circuit

cheers Neil

[stevev]

do you think using 1 28oz tube of the gg compound per 2400 x1200 is enough

i believe there is a minimum rate of applcation or the GG won't be very useful. I believe there's also a maximum rate after which you don't get any increase in isolation. You should be able to find that info on their website, but 1 tube per sheet does sound a little light. I ended up using 42 tubes on my ceiling which comes in at around 2.6 tubes per sheet.

and then the gg sealant all around the edges and any little gaps

yep. airtight.

do you have a seperate power cable for lights into your room or do you power lights and all equipment off the same circuit

As far as the studio mains cable goes it's a single supply for power, lights and air-con which is connected from my house switch board and has it's own circuit. In the studio switch box however, there's a circuit for each of the air-cons, three for power, one for lights, and one for the monitors.

All the power and lighting is star-grounded, which means they all have their own seperate earth that runs back to the mains earth. I'm not sure how necessary that was as Australian earth wiring is different to the States, but we did it anyway as it's not that much more work.

All up I think I ended up with 40amps in there which should be enough to run just about anything. 6 power points in the control room with another two dedicated to the monitors and another 6 in the live room. All the lights are LED which don't draw a lot of current.

[stevev]

i was wondering what type of backer rod you could recommend using?? around the outside of each wall, joins, maybe a 5mm gap between sheets and the floor and 5mm between wall joins,

Hey Neil, I can't remember exactly what the backer rod I used was, but it's a pretty standard type of thing that you should be able to get from whoever is supplying your plaster.

From memory I had a 10mm gap where I was joining my plaster ceiling to my brickwork with 10mm backer rod and GG acoustic sealant. For all the internal joins I didn't use any backer rod at all as the sheets were butt joined so a bead of sealant on its own was fine. I also didn't use backer rod on the wall to floor joins as the gap was only 1-2mm in spots so again, the sealant on it's own is fine.

I'm not sure if that answers your question but overall i'd say if you can keep your floor to wall, and wall to ceiling tolerance down to 5mm then you probably won't need backer rod at all.

[Soundman2020]

i believe there is a minimum rate of applcation or the GG won't be very useful. I believe there's also a maximum rate after which you don't get any increase in isolation.

One tube per 4x8 sheet is the minimum, two is good, and three is the maximum.

- Stuart -

[neilstar]

thanks again for quick response, will post some pix soon,

cheers Neil

[neilstar]

Hi stuart, thanks for your input

do you think adding the green glue compound at either 1or2 tubes/sheet will make much difference to final isolation result?,

300mm air gap between walls, completely filled with insulation
soundscreen 3.1 insulation approx 25kg/m3 110mm and 190mm approx 12kg/m3 lightly packed

22mm ply screwed over the entire internal wall frame
2 layers of 16mm fyrecheck , will green glue compound make much difference to final isolation results???

green glue compound expensive stuff here in aus $308 for a box of 12, probably need 3 or 4 boxes

cheers Neil

[stevev]

300mm air gap between walls, completely filled with insulation
soundscreen 3.1 insulation approx 25kg/m3 110mm and 190mm approx 12kg/m3 lightly packed

22mm ply screwed over the entire internal wall frame
2 layers of 16mm fyrecheck

I'd say you're looking pretty good there without the GG Neil. As long as you pay close attention to detail on every layer and make sure there are no air gaps between any of the ply/gyprock sheets and any of the wall/floor, wall/ceiling joins. Also, stagger all these joins as far as is practical.

Stuart will be able to give you a better idea of the isloation you could achieve with that kind of construction, (he's pretty sharp with the maths of it ) but a lot of it will depend on how well you seal it all up and the attention to detail in doing so.

[neilstar]

hi steve , what was yr best method of cutting the soundscreen, trimming to fit odd places,??

cheers Neil

[stevev]

A 'snap off blade utility knife' worked best for me Neil. When they're fully extended you get about 100-120mm of cutting edge. Easy to find at any hardware store.

[BaseApe]

Just came across this thread. Exactly what I needed as I'm evaluating a shed that is almost an exact replica of Neil's

Neil - Are you able to let us know the rough cost of your build? Sounds like you got quite a lot of the materials for free but it would give me a ballpark figure. Also how much sound reduction you ended up with. I'm assuming you're more or less finished although the lack of posts recently might suggest otherwise

Any pics of where you're at now?

Cheers,
Simon

[neilstar]

Hi Simon,

thanks for email, im still alive but i did slow down the building process after lots of reading and learning about what i was trying to do, and it seems the more i read and learn the better i wanna do it, which in turn means more money, more materials, but i have been extremely lucky regarding materials, and i have basically done all the building and work myself hours and hours and hours, with the knowledge and expertise of friends which are local builders, i am still in the process of lining the internal walls 1st layer, 22mm plywood which means getting all the insulation in, air con 1st fix, electricity, wiring for power and lights, more or less definetly not finished,

regarding how much i have spent so far, i hate to think about it, but if i had to go buy all the timber, OMG,


i will try and load up some pix when i get a chance,

cheers Neil

[neilstar]

some pix as requested