Help - I think I'm about about to do something dumb

Thanks for taking an interest Xspace. Can I just clarify something, just to get it firmly fixed in my brain. in the MSM idea - the outer perimeter (the existing walls of my warehouse) acts as one of the masses - I would then need to build one stud wall with mass on it (4 layers of 15mm and 12.5mm plasterboard in my case) and fill the gap between the existing wall and my new stud wall with insulation (100mm)? and then have double studs between the rooms?? This would give me MORE isolation than if I built a double stud wall (with the same amount of mass) inside the existing wall of my warehouse? chris

reservoir1 wrote:

in the MSM idea - the outer perimeter (the existing walls of my warehouse) acts as one of the masses - I would then need to build one stud wall with mass on it (4 layers of 15mm and 12.5mm plasterboard in my case) and fill the gap between the existing wall and my new stud wall with insulation (100mm)?

Exactly.

Let's break this down for you. What you are building is several boxes inside a larger box (refer to xspaces pic) the larger box is your original structure. This is your first leaf. Let's make sure this is only one leaf, no air pockets anywhere inside the walls? Now this outside leaf has as much mass added to it as possible without creating air pockets right? And there is no holes in it anywhere either ? If you filled it up with water it wouldn't leak anywhere, even if the building was turned upside down ? now the inner boxes. Every room inside of this building will be absolutely independent from every other room (except for the floor). No boards, bracing, anything, touching between rooms. Now each of these rooms will also have an independent ceiling. The 2nd leaf is created by putting mass on only one side of the studs on the walls and ceiling. At this point you will have 2 independent, isolated leaves of mass separating every inhabited space within your studio and also 2 leaves of mass separating the interior from the exterior. This is the basic concept for everything you do in studio construction. For details on how to build this refer to Rod's book. I just want to make sure you are absolutely clear on this concept because some of your questions lead me to believe you are not. Steve

Thanks - you just saved me a whole load of cash - not to mention trouble!! i thought i was missing something. Doh! Am I also correct in saying that i would then need to fill/make good any holes in the existing walls - large ones with Rockwool and cement (as per Rod's book). smaller ones with cement??

Is this what you mean steve? blue is outside (warehouse wall) yellow - Control room, purple - amp room, green - live room. all with their own ceilings. The orange is the kitchen/entrance lobby - i'll have to build extra stud walls for these, as there's nothing there at the moment, as an extension of the original 'outer' wall - that large block of black is a brick wall, which i need to isolate. I realise that this will make a 3-leaf wall, but think I may have to live with that, my electric board is in that area (orange) too, and I thought it better to build around that rather than have an access panel to it in the main studio - unless anyone has any better ideas? one thing you said i don't get....... "Now this outside leaf has as much mass added to it as possible without creating air pockets right?" do you mean that i need to add mass to the original wall? Sorry for all the questions cheers chris

Yes, this is what I am referring to. Good thing Steve came along and explained my thinking to you ;)

"Now this outside leaf has as much mass added to it as possible without creating air pockets right?"

This is not a concern for you because you have a brick exterior wall boundary. It would only apply if you had already added more mass to the exterior wall by means of more framing or furring or in some way creating any air space between additional layers of mass and this exterior wall, which you have not.

Thanks both - i think I've finally got it! I'm going to carry on beefing up the ceiling, fill all gaps and holes in the existing structure and build my amp room as per your advice to see if what I'm doing works!! will post pics - it's gonna take me at least a few more days to beef up the ceiling anyhow thanks very much, again chris

sorry, me again, questions, questions! I will begin building the walls for my amp room soon, to test the level of isolation I'm getting - one question on the left of the photo, there are pipes for the upstairs toilets - nice! One of my walls will need to go in front of these pipes, about 50cm away from the wall - do I fill that void (between existing wall and new wall) with insulation, or box the pipes in, then fill the void - or something else? cheers chris

can't believe how long it's taking beefing up the ceiling! it's taken 4 guys 4 days to do a quarter of the space. As it's an old building, all the joist sizes are different, plus the gaps in between one single joist varies. This is one job, i don't want to do again, 3 layers of plasterboard with green glue, backer rod and caulk - I'm glad I've got a hat! No pictures as my arms hurt too much :roll: Anyway. have decided to box-in and insulate around the waste pipes, hope that's the best way to go? cheers chris

hey chris, me too had the problem with the waste pipes and I decided to wrap the pipes with rockwool and carefully cared about not touching the inner leave of my new wall in any kind with the rockwool wrapped drain. 1st layer gypsum showed me that it was a gooood decision. 2nd layer was...i dont know...was there anything??? i was worried that if i box the drain in a gypsum box i would possibly create a 3rd leave so i would make things worse. a drain is a leave too...at least i guess...erm...i can't say if it is so but after my 1st recording session i can say: neither the one from above nor from downstairs recognized anything since i came along to ask if they heard sth...(i hope u got what i mean....??) maybe they were not on toilet but they were there :) hope that helped a little... cheers, carsten

but to be honest... i don't know how it would have been if i had built a box around the drain. sssssoooo... no help anyway...maybe. hmmmm. xSpace? Soundman? anyone? cheers, carsten

:D does it need to be accessable? what if they have an exterme blockage and the plumber needs to get in there.

shit happens. :shock: but maybe hmm. i dont know... some kind of maintenance cover to be on the "safe side"? c.

carsten_d wrote:

shit happens. :shock:

Funny guy! Yea, the clean-out access on the pipe should be easy to get access to. You wouldn't want to close that off and run the real risk of having to get into it at a latter date meaning cutting into your isolation.

Thanks guys, nice to have you pitch in Carston - I read your thread last night and know that pay alot of attention to detail! There's an access point, which is not too much of a problem in worst case can be go at upstairs through the floor boards. So, is boxing in better, would that create another leaf, as I wouldn't box all the wall, just the area around the pipes and it'd be attached to my existing wall? cheers chris

chris, thanks. but: the more details...the more confusion...the more shit in the head... now that i read your thread (not everything but the overview and a little more) i'm getting it better. you want good GOOD isolation and you need to have access to the waste pipes (lilith & xSpace are right... kind of detail i ignored) but you said you'll have 50cm between your new wall and the existing wall. that must be enough for a small person to go between. but if you box it someone has to rebox it in case of ...shit... holy shit. i dont have a clue. :oops: i would box em in and pray that nothing never ever happens. but i guess this is not a solution! sorry. i'm not able help. cheers, c.

Thanks Carsten - I know what you mean about the more details, the more confusion! Although I think I'm getting near to the point of understanding things, but my head (as well as my arms) hurt! I'm gonna box in the waste pipe, We'll be able to get access from above if we need to in the future. Did you find out if the boxing in constitutes as a leaf or not? cheers chris

here are some pictures: beefing up the ceiling and boxing in a waste pipe. The ceiling ones ain't that interesting, it's a pain staking job, getting through it slowly - using tons of caulk. BTW - It's true - double your budget and time-frame! And wear a mask/goggles and long sleeves whilst handling rockwool -that stuff really itches chris

Looks good, Boxing it in was what I would have done too. Sorry I didn't get back to you earlier but you seem to have this under control. Not enough time for much posting. Steve

thanks for the words of encouragement steve. It's good to know i'm going in the right direction

a couple of wall questions for anyone who's out there: I've decided to go for an inside out wall - with a normal ceiling - as discussed earlier in the thread. I'm planning on putting 4-layers of plasterboard on the walls, 2 on the ceiling, along with the 3 layers of beefing up between the joists. I know (think) I have to match the mass on the walls and ceiling. Does this (wall mass) sound OK or overkill? My reasoning is that I'd rather overspec, but don't want to waste cash. Also: i think I'm right in saying that I can put the insulation (60mm in my case), which is glued to my new walls against my existing walls? If that's Ok, would an air gap (with no insulation), be of any help in isolation. i.e existing wall - air gap - insulation attached to 4layers of plasterboard attached to stud wall with more insulation in? thanks chris

Yes an air gap will help. Also think about attaching insulation to your exterior wall. Steve

cheers steve - is attaching insulation to the exterior wall better than attaching insulation to the plasterboard then? sorry slightly confused also, if the air gap will help with isolation, why would i then attach insulation to the exterior wall? cheers chris

"I've decided to go for an inside out wall ... I'm planning on putting 4-layers of plasterboard on the walls" A typical inside out wall is going to be raised to an existing wall. This means you will be attempting to raise a four layer sheetrock wall and I can tell you not only is this getting into the area of the impossible it is approaching waste:) If you are going to use four layers then you may as well install the sheetrock on the interior side of the framing and get the benefit of the air to enhance the low frequency reduction. It makes very little sense when you consider the reduced air pocket and the reduced low frequency isolation to attempt some thing like this. It will be difficult to raise a wall of this type, so you guys be careful.

also I'd like to see your most recent design. with top and bottom plates drawn in. I'm starting to worry, as all I keep seeing is these floating studs. hate for you to miss calculate the final height.