Ian Stirling wrote in message ...
Lobster wrote:
I want to apply sound insulation to an internal soil pipe, which runs
vertically from ceiling to floor. I've built a timber frame around it,
which I'm going to cover with two layers of 12.5mm plasterboard and have
skimmed. I know the ideal way would be to fill the boxing with sand to
deaden the sound, but that would cause too much grief (can't quite imagine
filling up all my boxing - which has to be quite large - with sand; plus
there's a rodding eye at the base for which access is needed). So I
propose to fill the void with Rockwool.

The absolute best improvement you could probably get (other than sand)
would be to decouple the two layers of plasterboard from each other a
bit.
This would stop sound travelling directly from one to the other.
I don't know the architecture, but would putting the first layer of
plasterboard on, and then building a second structure, only connected to
the first at top and bottom around it, on which the second layer is
connected be possible?


Or perhaps glue on a layer of under-laminate-floor 3mm sound absorbing
sheet, then glue your last PB layer onto that. Dont screw through it,
as that will largely defeat the working of the mat. Note I havent
tried this. Also note that each measure will help some, so a
combination of approaches is what will produce best results.

Regards, NT