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Dealing with impact noise

Posted: Thu Jan 28, 2021 6:54 pm
by Julián Fernández
Hey guys, how are you? Long time no see! :D

I have this private teaching space on the first floor... Slab construction. Room is working as supposed, but I´d like to improve the impact noise leaking downstairs.

I was planning on using Super W pads and 50kg/m3 fiberglass... 2 layers of gypsum and wood on top. Should I place those 2 layers over the pads and wool or it would be best to build a frame...
I´m afraid floor will feel kinda shaky if I just place those 2 layers and screw them together...

Any suggestions? Sketches?

Thanks so much!

Re: Dealing with impact noise

Posted: Fri Jan 29, 2021 1:43 am
by gullfo
might be better to go with cement board instead of the gypsum - less likely to facture or crumble, plus more density - maybe ply + cement board + ply will be more rigid and provide the mass - careful distribution of the W pads - should be stable - consider live room weight in planning the isolators.

Re: Dealing with impact noise

Posted: Fri Jan 29, 2021 3:55 pm
by Julián Fernández
Makes sense. Appreciated!

What about placing the boards directly over the pads vs building a frame to place the boards (filled with insulation in both cases)

Thanks!

Re: Dealing with impact noise

Posted: Sat Jan 30, 2021 3:22 am
by gullfo
that will depend on your load structure - i think without the boards should be ok as adding the runners will increase the air space and overall height.

Re: Dealing with impact noise

Posted: Sat Jan 30, 2021 4:54 am
by DanDan
Glenn, Paul, will have more actual build experience, but my gut is saying 50KG seems very light.
The products sold for underfloor around here are typically say 140KG.
I wonder are they springy enough and do they stay that way.
How about more specific products. Regupol, Alpha Akustiki?

Re: Dealing with impact noise

Posted: Sat Jan 30, 2021 10:27 am
by gullfo
the 140kg sounds like cement and if an option, that would be a good choice because it's probably easier to get the spring in the isolation correct and less susceptible to load shifting - with the caveat the structure needs to be able to hold and not also not become a resonator...

Re: Dealing with impact noise

Posted: Mon Feb 01, 2021 10:27 am
by DanDan
Nominal density between 60-140KG....... https://pim.knaufinsulation.com/files/d ... e599dd.pdf

What is your take on Regupol etc. Glenn?

Re: Dealing with impact noise

Posted: Mon Feb 01, 2021 12:07 pm
by gullfo
thanks Dan. i'mma was thinking in cubic feet... about 10x less :-)

Re: Dealing with impact noise

Posted: Tue Feb 02, 2021 4:29 am
by DanDan
Must be difficult to find footware......;-)