In article ,
Kevin Webb wrote:
Thanks for the replies, they seem to confirm my feeling that light
insulation wouldn't be very effective.

The plasterboard idea sounds as though it would be both cheap and
effective but I think I should keep the boxing ventilated which would
probably allow the noise through.

I'm not sure why you think the box should be ventilated? And as you say,
it rather defeats the object of the exercise. Ventilation would only be
required if it's likely to get damp - you don't for example provide
ventilation for the inside of a stud wall.

Insulating the pipes directly with heavy pads to reduce drumming would
probably help a lot.

No it won't. PVC doesn't drum - try dropping a pipe made of it. Scaffold
poles drum. ;-)

I've just got to find where I can get this kind of material cheaply. I
did look for something similar whan I was trying to quieten a PC but it
doesn't seem to come cheaply. Does anyone know of a source?

I've bought it from car body paint suppliers. But it's still not cheap
even at trade prices - a box works out at over a quid a square foot. I've
not found anywhere that sells it by the panel.

Just box in your pipes with two layers of plasterboard on a rigid frame
sealed at both ends. This will work - reducing the noise to the point
where it isn't noticable. You don't need any fancy materials or special
techniques. I've done just this and it works.

--
*Learn from your parents' mistakes - use birth control.

Dave Plowman London SW
To e-mail, change noise into sound.