Update studio : new ceiling

[pulse]

Hi all,

I am new here, but I find this place full of good pro advices. So here I come with my questions, but before, it is better I explain a bit the story of the stud

I am from Switzerland and I bought a house three years ago and I did my stud in the double box garage below the house. I just a wall and a door to close the box. You can see the pictures of this work at www.pulseconcept.com studio section.

The walls have been doubled with rockwool (80 mm) and plaster. The goal of this was to stopped the sound so that it goes no way outside ... The goal was reached ! My neighbour are happy and so I was. I say I was cause now I am not

The thing that I totally forget was the ceiling. I was covered by sagex (polyethyrène) and I added one couch of decorative sagex ... Good looking but very poor soundproofing

I play the guitar and sings and make music with electronic stuff (I told me no more bands). But I changed my mind, and the result is ... I play with a drummer and bassist now and the level we play is quite loud ...

The walls are still ok, quite no sound outside the house (so no prob here)
but for my wife it is a nightmare as the sound stays in the house

So I am gonna update the studio by soundproofing the ceiling.

Here is what is planned after having seen a lot of pro people.

My ceiling is a "dalle à ourdis" meaning I have a lot of gaps in my ceiling. So I am filling theses %&/ gaps with acrylic mastic (hard and slow work ;-(

Then (my command is already done) I will place the following stuff to the ceiling from top to bottom :

- wood "squares" in order to do panelling ... I will glue felt on the top of the wood (the part that will be strecthed to the ceiling). The goal is to reduce vibrations (I dont have enough money to go into RC channeling).

- between this wood pieces I will place isover R confort (www.isover.ch) it is glass wool but special for acoustic treatment.

- then I will place idikell (it is an swiss produt like auralex sheetblok + but cheaper) on fermacell panels (18 mm thick). Fermacell is a very heavy and strong product (gypsum fibers)

- these heavy panels (idikell + fermacell) will be fixed to the wood constructions (that will be screwed before to the ceiling)

- then I will check the sound and see how much absorbing I need ...

Question:

The joint between the new ceiling and the existing plaster-rockwool walls will be made with silicone (I know I have to keep a 5mm gap between ceiling and wall)

My problem is more about the walls. I explain the "I" are the walls and the "i" are the rockwoll-plaster walls). "S" is sagex (polyethirèen) The thing is about height of insulation

before

Old "dalle à ourdis" ceiling
ISSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSs
Ii
Ii
Ii
Ii
Ii
Ii
Ii floor


Now it is like this

"dalle à ourdis" Ceiling
I <- that gap here should stayed empty ?(now I still have piece of old sagex cause to throw
Ii all these unuseful material I cut it next to the
Ii wall)
Ii
Ii
Ii
Ii floor


What is the best solution ? a) or b) or c) ?

solution a) "E" empty
"w" new ceiling : glass wool and pieces of wood "p" : pannels of fermacell and idikell

"dalle à ourdis" Ceiling
IEwwwwwwwwwwwwwwwwww
Iipppppppppppppppppp
Ii
Ii
Ii
Ii
Ii floor

solution b) "S" sagex ... lets keep it as it is now (after cuting the old material)

"dalle à ourdis" Ceiling
ISwwwwwwwwwwwwwwwwwww
Iippppppppppppppppppp
Ii
Ii
Ii
Ii
Ii floor

solution c) "w" glass wool will filled the gap. With that case the ceiling insulation will touch the wall (not by solid way but by wool)

old ceiling
Iwwwwwwwwwwwwwwwwwwwwww
Iippppppppppppppppppppp
Ii
Ii
Ii
Ii floor

YOUR HELP IS WELCOME !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

thanks in advance
bye
PHil

[pulse]

nobody can help ? my schemas are not easy to understand ?
thanks

[JOHNNYGATE]

for isolation you have to follow the Mass air Mass theme. I would concentrate my efforts to accomplish this to the best of your ability. There are many other factors that need to be addressed also, but that is the concept to design around. As you plan this members here will gladly help your design. Remember Mass air Mass is the best isolation.

[pulse]

THANKS

so solution a) should work ...

I ll see !

I know about that air mass thing ... that's why I put strong heavy things and then glass wool (light thing) ...

[knightfly]

It would help a LOT if you can post an actual drawing of some sort - I've never been able to see anything from these ascii type "drawings", nor can I see what's "hidden" in those funny little "dot matrix" pix -

Basically, though, Johnnygate's right about the mass-air-mass thing. What some people get confused over, though, is what is "mass" and what functions more as "air" -

Basically, any material that you can NOT blow through is mass - even closed cell foam, which weighs nearly nothing, is technically "mass" and not "air" - A hollow concrete block wall is already a mass-air-mass system, because the air gaps in the blocks are just that - air.

Any time you put a layer, no matter how thin, of open celled insulation (fiberglass, rockwool, mineral wool, slag wool, open-celled foam) you've just put in an "air" space - you only get ONE of these, then you're DONE - the mass on either side of that is then considered as two separate masses, with an air space between.

I checked your website out and found no pix that would help explain your ceiling construction, but if you have smoothed out the wrinkles using some kind of patching plaster, then you need a wide, insulated, air gap and a second mass (this is assuming your construction ABOVE all this has no more "layers" to it.

To help kill footfall noise from above, you may want to use resilient mounting for the inner leaf of mass - also, I'm not sure what is holding your ceiling up - before adding more weight, we need to clear this up as well... Steve

[pulse]

okay so I am gonna try to takes pictures of the ceiling and the we can go on with the talking ...

true : I finished the first part of the studio with the mastic thing .. dont like that but i think it will help a lot for the db stop thing ... the mastic I use is a stop air thing so I dont thing a need to put a second one (it stays elastic even when it is dry)

the dalle à ourdis is a system that mixed blocks and iron ways .. but I will post pictures ... (if I know how to do it in a post ...)

like we say in french : "affaire à suivre" !!!

[pulse]

here are 3 images ... I ll try to put them in this post

[pulse]

the third one

[pulse]

the third has a problem to upload ...new try

ok seems that the third is not able to be loaded

but it is not a problem

on the first one you can see what I call dall à ourdis with the old sagex ....
on the second one you can see the wall that doesnt go to the ceiling (the blank) on the left a old piece of sagex and then it is empty ...

so now you should better understand my ascii explanations ...
thanks to respond
bye

[pulse]

the round things on the ceiling are old pasting (for the sagex) ... no probs !

[pulse]

one more try .. I looked at the size of the files and that one was maybe a bit too big ... lets try

[pulse]

here you can see how I filled the gaps with the mastic ...

on the picture with the wall (yellow) you can also see that ...

the first picture is just the ceiling with no filling (yeah still lot of work to do) ....

I ordered today :
- 30 fermacell 1m x 1m50 x 18mm
- 90 idikell 1m x 0,5m x 5mm (like auralex sheetblok +)
- 22 pieces of wood of 5 meters
- joint for fermacell

I still have to order :
- 5 piece of Isover (glass wool) of 15 meters each one
- different things like screws and so on ...

It is like I begin to see the mountain I will have to climb dont like that very much !!!!

[pulse]

bump !

[knightfly]

Still trying to figure out how to answer your questions -

Is this the product you call sagex?

http://www.sagex.co.za/

IF so, it's light weight, not good for mass, and not an air space (EPS is closed-cell foam)

Couldn't find much on "fermacell", other than it seems similar to gypsum wallboard.

Mass loaded vinyl is normally more expensive for the same results as gypsum, and harder to seal/install/calculate -

I tried earlier to explain the mass-air-mass principle, including what should be considered mass, etc -

Now, I'm trying to figure out if you've already done some non-standard things and you want me to tell you they will work, or something else? Maybe you could re-state your questions now that we have a bit of background... Steve

[pulse]

okay so you are right about sagex, it is this "bad thing" !

the thing is my ceiling was totally covered with this sagex ...
I removed it but not where i put "the new walls made of rockwool and plaster" .. you can see it on one picture

the global question is :

should I remove the rest of the sagex that stays between the new wall and the ceiling before putting the new ceiling ?

If yes, should I leave this space empty or not ?

If not with what should I fill this space ?

Better this time ?

thanks to answer all my posts !!!

PS : I think I didnt thing I have beeing doing non standard things ...
PS2 : you can find fermacell on www.fermacell.com. Yes it is like gypsum but stronger and heavier