Impact Noise problems (rain) with standing seam metallic roof

[chickenfingers]

Hi

This one is slightly long and if possible I need comments on the numbered sections below:

1)
I have an impact noise problem with a standing seam metallic roof due to the rain, which gets quite bad during heavy rain periods.
I have thought the way forward is a suspended ceiling of 13mm drywall with say 50mm fibreglass (or any other absorbent material) in the cavity. The drywall alone is likely to give me >20dB above 125Hz (is it necessary to put a thin damping layer at the perimeter of the ceiling? where it meets the sidewalls, will vibrations be an issue there?). Air cavity aorund 200mm (I have enouch room). I will hang the drywall from the beams holding the standig seam roof using some sort of acoustic hangers so that vibrations don´t travel thru.

WHAT DO YOU RECKON?

2)
Is there any damping product in the market I can lay under the metallic roof to prevent vibrations from happening in the first place. Will a sprayed layer of polyurethane (4-6mm thickness) help in any way? Is polyurethane a good dampener? I read here http://www.azom.com/news.asp?newsID=12833 that an elastic polyurethane was being used to dampen train vibrations by filling the cavities between the ballast stones with a special composite of it.

3)
I have been offered by roof-ceiling suppliers a complement to the existing roof. This is a sandwich like setup with another layer of the same metallic tile (these are of aluminium or aluzinc?? of 0.6mm thickness and 5.68kg/m2) and 50mm of fibre glass or polyurethane foam in the cavity. I reckon this system will be nowhere near the one I proposed above, as the density of the drywall is larger than that of the aluminum tile and so is the air cavity.

4)
What noise isolation system is generally used under standing seam roofs, when the problem is impact noise (rain)?


Thanks a lot for your help!!!

 

[Savant]

Sergio,

I sent you a PM regarding this post.

 

[bpape]

For impact noise as you're experiencing, my suggestion for a reasonably priced solution would be to fill the cavity with less dense insluation. You could also do MLV below hung loosely but that will be terribly expensive to do.

Bryan

 

[mtrycrafts]

Hi

This one is slightly long and if possible I need comments on the numbered sections below:

1)
I have an impact noise problem with a standing seam metallic roof due to the rain, which gets quite bad during heavy rain periods.
I have thought the way forward is a suspended ceiling of 13mm drywall with say 50mm fibreglass (or any other absorbent material) in the cavity. The drywall alone is likely to give me >20dB above 125Hz (is it necessary to put a thin damping layer at the perimeter of the ceiling? where it meets the sidewalls, will vibrations be an issue there?). Air cavity aorund 200mm (I have enouch room). I will hang the drywall from the beams holding the standig seam roof using some sort of acoustic hangers so that vibrations don´t travel thru.

WHAT DO YOU RECKON?

2)
Is there any damping product in the market I can lay under the metallic roof to prevent vibrations from happening in the first place. Will a sprayed layer of polyurethane (4-6mm thickness) help in any way? Is polyurethane a good dampener? I read here http://www.azom.com/news.asp?newsID=12833 that an elastic polyurethane was being used to dampen train vibrations by filling the cavities between the ballast stones with a special composite of it.

3)
I have been offered by roof-ceiling suppliers a complement to the existing roof. This is a sandwich like setup with another layer of the same metallic tile (these are of aluminium or aluzinc?? of 0.6mm thickness and 5.68kg/m2) and 50mm of fibre glass or polyurethane foam in the cavity. I reckon this system will be nowhere near the one I proposed above, as the density of the drywall is larger than that of the aluminum tile and so is the air cavity.

4)
What noise isolation system is generally used under standing seam roofs, when the problem is impact noise (rain)?
Thanks a lot for your help!!!

Do you have access to the underside of that roof? Blowing some deadening material on it should reduce the noise quite a bit. You could experiment with a small or larger sheet

 

[Rickster71]

I've found that adding another layer of insulation, (over the existing layer and at a 90 degrees angle) in the attic really does the trick.
Since most attics aren't insulated enough anyway, it will help with your energy bills too.