How dense is too dense? (product evaluation)

[leon.payne]

Hi all.
In searching around the net trying to find insulation materials for the inside of an inside out wall design, i came across dense fibre matting from a company called noise stop systems.

http://www.noisestopsystems.co.uk/dense ... ng-69.html

if you have a look at the data sheet towards the bottom of the page, it gives some very promising absorption coefficients.

questions is, is there a limit to how dense the insulation can be before it has an adverse effect to sound reduction?

[gullfo]

looks to be mineral wool... you could check Bob Golds site for absorption coefficients and compare it to other products which may be less expensive and just as or more effective.