Sound insulation & resilient bar to posijoist?

[mvincentd]

Resilient bars have just come on my radar along with the realisation that having posijoists separating ground and 1st floor makes for a potentially fiddly job.

If i'm understanding correctly, I've got to stuff maybe 100mm of acoustic wool in there, but unlike solid joists the metal webs create loads of awkward spaces that a simple slabbing approach won't infill. Do people generally bother about this or settle for a less discerning job......and does it make a tangible difference?  Likewise do resilient bars make a tangible difference.......theyre not specced on my drawings but the theory behind them is attractive given I feel my posi's at 600 centres in this position exhibit a tad of bounce/vibration?

[ProDave]

No problem fitting sound insulation between posi joists

 

 

Just some odd bits of 4*1 slotted through to hold it in place (okay, yes I admit, from a pallet or 2) Didn't bother actually filling the space between the webs.

[Moonshine]

My opinion is reslient bars are a bit over kill in a domestic floor, and will provide 1-3dB in airborne sound insulation from memory, I can dig out the data on it later.

If you are concerned about bounce the resilient bars won't really help that, as they are flexible themselves

On site I have actually seen a developer counter baten under the joists to firm up the floor flex, and would give you something to hold the insulation in as above.

 

Edited October 29, 2018 by mike m

[mvincentd]

Thanks, it's sounding like the simpler approaches might be better........thats refreshing for once!

[Gav_P]

Isn’t the idea of resilient bars to effectively separate the plaster board (or acoustic board) from the joists... thus breaking the direct contact route of noise transfer? So not addressing airborne noise as much as walking or jumping about from upstairs? And posi joists most do this better than normal joists anyway don’t they? 

Or have I scooped too much red wine tonight? 

 

I opted for acoustic slabs between joists, rubber strips between joists and floor boards, and double sheets of 12.5mm standard plasterboard... all the cheapest option for me and seems to work as I can’t hear my daughter on her drum kit.