Dealing with impact noise

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!

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.

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!

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.

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?

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...

Nominal density between 60-140KG....... https://pim.knaufinsulation.com/files/d ... e599dd.pdf What is your take on Regupol etc. Glenn?

thanks Dan. i'mma was thinking in cubic feet... about 10x less :-)

Must be difficult to find footware......;-)