Rehearsal room in a room

[djamon]

Hello all,

That's my first post here, so let's introduce myself :
I am writing you from France, I play drums in a band, and I plan to build a rehearsal room in a dedicated building.
I have quite a good budget, and I want to do it right.
My main goal is to be able to practice drums, or rehearse with my band, all night long without disturbing my neighbours.

I have read quite a lot of threads about sound insulation, so I think I nearly know what to do to achieve my goal. But som structural questions remains, so here it is :

1) Existing building :

- sky view :

- inside views (without and with frame) :


- cut views :



The rehearsal room will be in the bigger room of this building.

some more details, and things that have a little changed since I made those pictures :
- The building is approximatly 30 meters from the closest neighbours
- It is made of 15cm hollow concrete blocks
- there is a ceiling mounted on the frame in the bigger room : 1,8 cm gypsum drywall (I can't double it because the frame accepts only 20 kg/m², I plan to blow in fiber-glass or cellulose over this ceiling to reach this maximum mass of 20kg/m² and for thermic insulation)
- inside wall are about to be covered with 2-3 cm of gypsum that will touch this new ceiling, in order to make the room hermetic (not really because of window and doors openings) and
- the roof is made of tiles
- the good joke is that the existong concrete floor is not flat (see the 2nd cut view), it has 8cm of level difference in the length of the room...

2) What I plan to do (a box in a box) :

a. external box

- a window will be put in the window opening (on the concrete blocks) with a resilient band. I already have this window : 1,00x1,30 meters for approximatly 150 kg, it has 3 layers of glass, the middle one ir not parallel to the 2 others. This window comes from a well known french studio. The window will be mount in order to be hermetic. For your information, I plan to put some drywall on the other side of the wall directly on the concrete blocks.
- An interior door will be mount on the interior door opening, I plan to get a 40 to 50 dB soundproof door. It will be mounted on the side of the other room, and will be hermetic too.
- I plan to change the external door (with 2 openings) with a 50 dB soundproof door (with 2 openings too, like this one : http://www.huet.fr/porte-technique/item ... gory_id=27 or any equivalent for an outside application)


b. inside box

- make a reinforced concrete slab over resilient cones. What thickness do you think is enough ? 12 to 15 cm ? I don't want it to be too thick, to maximize the inside ceiling height.
- build walls over a resilient band with a stell structure. It will be set only on this floating slab.
- Build a ceiling that will be mounted only on those walls. Wooden beams will hold it. I plan to use beams of 5,40m length, and section : 17,5 x 7,5 cm
- The inside room will have this shape, to help with later acoustic treatement:
- Acoustic doors and windows will be mounted on the inside floating box.

Here are some views :
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c. HVAC

- I plan to add a air controlled system, but I will show you in later post.


3) My questions :
- What thickness for the concrete slab ?
- What kind of reinforcement for the concrete slab ?
- What distribution for cones under the concrete slab ?
(I mean, the slab must not break because of the walls+ceiling weight in its permimeter...)

- What composition for walls and ceiling ? I was thinking of something between 45 to 60 kg/m² of drywall (DW) with GreenGlue (GG) (first numbers is drywall thickness in mm):
- 18DW + GG + 18DW + GG + 18DW ?
- 18DW + 15DW + 2xGG + 15DW + 18DW ?
- 25DW + GG + 18DW + GG + 15DW ?
I heard that with green glue, it does not matter if the drywall leaves have the same thickness... Right ?
- The weakness of my structure may the the ceiling, because of the existing ceiling that is "weak" compared to concrete walls... what do you think ?

Thanks in advance for any help !

Regards

[djamon]

Hi again,

This post to add some general information about my project :

- I plan to build a rehearsal room (I may use it to record too, maybe as a home theater, but that is not the point right now)
- With my band we were told we play loud, so I would suggest around 120 dB
- My closest neighbours are at 30 meters, but the most sensitive ones are at 50 meters.
- The level of insulation I would like to achieve is : my neighbours must not ear anything inside their respective houses (with closed doors/windows). I think I need somthing like 65 dB of attenuation.
- It may not be possible to achieve this level of attenuation, so the better will be ok for me.
- My project is in stand by while I am gathering the last pieces of information I need. But the construction will happen as soon as I know thoses details, and during next summer (now -> August 2016)
- I know my project has some weak points (mass of the outer ceiling mainly I think), but I will deal with it. and my questions are mainly to find the solutions that are consisent towards this weak point.
- The project will be a room in a room with a 15 to 30 cm air space betwean inner and outer walls (20cm between inner and outer ceiling).
- The budget is around 20 k€.

Thanks, Regards.

Djamon.

[ABitAnalog]

Hi again,
- My closest neighbours are at 30 meters, but the more sensible ones are at 50 meters.

Thanks, Regards.

Djamon.

It probably makes sense in context, however, I wanted to be sure that something does not get lost in translation.

The word you likely mean is "sensitive," which is the best translation of le mot français "sensible."

Le mot "sensible" en anglais veut dire plutôt raisonnable.

It is possible that the neighbors 50m away are both sensitive and reasonable. Then, it works both ways.

[djamon]

Yep you are right. thanks for pointing this, I edited the post
(My english is not perfect )

EDIT: "Insulation" is also better than "isolation" ^^

[Soundman2020]

I think I need somthing like 65 dB of attenuation.

That's a very, very large amount of isolation! It is possible, but complicated, and expensive.

EDIT: "Insulation" is also better than "isolation"

To avoid confusion, we try to use the word "isolation" to refer to stopping sound from getting in and out, but "insulation" to refer to the fluffy woolly stuff that you put inside the wall. So "isolation" is sort of the same as "soundproofing" (which is a terrible term that we never use, as it is impossible), and also the same as "transmission loss", which is the more technically correct term, and "insulation" is the soft fluffy building material that you need to help you get "isolation".

- Stuart -