Celing soundproofing

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Celing soundproofing

Postby bolehnggak » Fri Feb 27, 2004 9:44 am

Hi,

I'm having problem with leakage from my ceiling. The room was a poor designed studio, so it already have the room within a room design, with inner ceiling and outer ceiling. Both are 3/8" gypsum board with no other treatment. Since they are already been built, any treatment which I could do is only for the outer ceiling. Any suggestion?

Ari
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Postby Jas » Fri Feb 27, 2004 10:33 am

Hi Ari,
Before anything else, make sure you have seeled any holes or cracks up. If it's already airtight you could glue a layer of 1/2" plaster right ontop of the exsisting layer.- srew fix em' into place, then remove screws and patch after glue has dried. Still not enough? A layer of sheetblock under (or over) the new plaster will give good isolation.
I'm also asuming you have some insulation in the airgap to damp resonances. If not you may be getting some bass absorbtion up there with a fairly narrow Q value. Particularly with one sheet only and if the joists are evenly spaced.
Just a thought.

Cheers,
Jas
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Postby Eric.Desart » Fri Feb 27, 2004 12:29 pm

Hello Ari,

Aren't you the John Sayers forum guy from Bandung Indonesia? I've worked there.
I lived in Ciumbuluit or something (name of street phonetically expressed, can't remember spelling).

Jas give you some good ideas, but I still think you should give a better description of your problem.

Complete build-up, distances, whatever.

BTW:
WELCOME to the group

Eric
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Postby bolehnggak » Fri Feb 27, 2004 5:20 pm

Thanks for the answer, Jas. Nope, there is nothing between the two ceiling. And because they're already built, there's no opening, so I don't think I could put some insulation between them. And the airgap is only 10cm (4").
To dampen the resonances, can I use glasswool? How good is it compared to rockwool?
If I could post pictures here, it might be helpful, but I don't see any 'ATTACH' button.
And to Eric, thanks for welcoming me to the list. Yes, I'm the Bandung guy from John Sayers list.
So, you lived in Bandung once, I studied in a catholic university on Jl. Ciumbuleuit. :) Do you plan to go to Indonesia again? Let me know, so we could meet. :)

Ari
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Postby Eric.Desart » Sat Feb 28, 2004 8:26 am

Hello Ari,

No I don't plan Indonesia for now. Not that I shouldn't like to. You have an incredible beautiful country. And Bandung has nice temperatures and climate. I'm not used to a tropical climate as in Jakarta. Within a few minutes all my cloths stick to my body, wet from the sweat. But it's not behind the door. You're literally at the other side of the world for me.
Jalang Ciumbuleuit. Thanks for reminding me! (I was there for ca 1 year, half the seventies, so will look different now)

Ari if what you're saying is that your ceiling is just a double leaf system with on both sides 1 layer of 3/8" gypsumboard without absorption in the cavity, then that's a poor insulating wall.

Is the the top layer the floor of the higher appartment?.
Ari you can't solve poor insulation by increasing absorption in the room (a bit, but that's relative insignificant).

Maybe it helps if you start reading Scott's Faq section.
In general: rockwool and glassfiber have roughly the same acoustic properties. So you don't go to make something suddenly good or worse by using one instead of the other.

You speak about leakage. What do you mean by that?

Ari: you're over there. So you know and picture what you're talking about.
People here must picture your problem based on some text only. The quality of your description will define the quality of the answers.

Is this a 3-leaf system or a 2-leaf system (often described by Steve in the Sayers group).
Are those gypsum panels without RC on common stuts?

I get the feeling that you are looking to improve something that is difficult to improve.

The wall build-up that you describe is poor. Having no absorption in between is bad. Having no RC but common studs for this lightweight wall is bad. Only one layer of 3/8 on both sides is very little for studio purposes.

Describe how this leakage manifestates. Overall poor absorption? Specific low frequent? High frequent?

And exactly describe those layers and studs from the upper floor downwards to inside the studio. I can not imagine that this 3/8 gypsum on top is the floor of an upper appartment nor the roof of the building.

Do you know what I speak about when I talk about a triple leaf system (Steve at John Sayers explained often)?

Ari:
1) If you ask a question, the readers try to picture your situation based on your text.
2) Just try to re-read your own text after writing it. Then imagine that you don't know the project your text is written about. That's how others read it.
3) Does your text then represents the problem accurate enough to get an answer?
4) Also imagine that there can be influencing paramaters you don't recognize yourself as influencing parameters. So it can be better to write a sentence too much than too little.
5) In function of isolation, if you build something in a room, even when completely decoupled, but relative close to the boundaries (walls, floor, ceiling) then you don't have just added additional insulation on top of the existing insulation, but you created a new isolation system where the existing boundaries of the room + the added insulation makes part from.

An example:
Suppose the existing wall is brique: you know the Transmission Loss curve.
You add a resilient Gypsumboard layer: you know the Transmission Loss curve of this gypsumboard.

Now one could think that you added the additional isolation of the gypsumboard to the existing isolation.
Well this is not true. If you should compare the resulting transmission loss curve of both objects combined, versus the individual transmission loss curves, you'll notice a complete different behavior that ranges from a significant loss in insulation to an extreme gain in insulation in function of frequency.
Why: because you create a new isolation system that answers to deviating physical principles.
Therefore: describe an isolation starting from and including the boundaries of the room (unless distance is very large).

In your description: you say the top layer is a gypsum board of 3/8". Then I immediately wonder: What's then on top of that? This hardly can be the floor of a higher appartment nor an outside roof. So something is missing here.

Best regards
Eric
Last edited by Eric.Desart on Sat Feb 28, 2004 2:47 pm, edited 2 times in total.
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Postby Ido » Sat Feb 28, 2004 1:26 pm



I heard say of being in a Indonesian jungle, and an Orangutan coming down from a tree, and hugging you..
Where do you sign up?
Ido
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Postby Eric.Desart » Sat Feb 28, 2004 2:57 pm

Ido,
Why don't you try yourself? :)
Who'll notice the difference? :)


This was really mean of me. I withdraw this message :):):)
(but don't delete it:))

This wasn't me,
but somebody who hacked my acount. :(
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