Resilient bars, mvhr & ceilings

[Jimbouk]

As we progress with the 1st fix, spent last week running almost 3km of a variety of cables around the house and through the posi-joists.

Next week will be tackling the mvhr ducting, which has got me pondering on acoustic insulation between the ground and first floor. 

 

At the moment planning on 100mm of earth wool slab, then plasterboard nailed to the posi-joists beneath. The joys of forums and the internet has now got me looking at resilient bars between the posijoists and plasterboard and sealing everything up with acoustic caulk (green goo). 

 

However wondering if it is worth it, surely the mvhr ducting will act as a giant diggerydo and the plenums breaking into every ceiling / room? 

Or is this even more reason to do it, as a mitigation exercise?

 

Also how should the ducting be installed to minimise noise, laid on posijoist bottom section, dangled down on cable ties in void or brackets screwed in?

 

Edited May 29, 2017 by Jimbouk

[Jeremy Harris]

I just cable tied the duct to the posijoist webs, and used 200mm of rockwool as acoustic insulation.  We don't have any detectable noise from either the MVHR or transmitted through the ducting.