how to insulate, soundproof when using posi joists.

[paulp4u]

Hi new to the the site just wondering if any one could give me a bit of advice.
We are about to fit the plasterboard onto the ground floor ceilings of a new build. The joists are posi joists with a chipboard deck laid on them for the first floor.
There are quite a lot of pipe runs, electrical cables, downlights going through and in them.
On normal I joists we fit rockwool tight between them before fitting the plasterboard to soundproof between the floors.

What is the best way to do it with posi joists.

Thanks.

 

[noseall]

Im not familiar with 'posi-joists' but if they are anything like 'easi-joists' then there is no need to fit acoustic insulation, so long as they are (i think) over a certain depth.