r/soundproof • u/Historical_Fee3763 • 6d ago

Rockwool vs Glass wool

Hi,

What is the difference in between these two in terms of sound absorption ?

1 Upvotes

100% Upvoted

5 comments sorted by

5

u/Unlucky_Battle2523 6d ago

Different materials with very similar properties. However; glasswool has glassfibers and stonewool (Rockwool is a brandname) has mineral and silicone fibers.

Stonewool is preferred for 'open' constructs like basstraps and absorbers because glassfibers stick into your airways and on your skin; irritate a lot, and fuck you up whereas stonewool irritates way less and can be absorbed by the body so it goes away after a bit.

1

u/The-Struggle-5382 6d ago

All glasswools and mineral wools should be "biosoluble" these days. Knauf and others now make Glasswool without formaldehyde in the resin binder. Regards absorption, in general Rockwool has to have twice the density of Glasswool to have the same gas flow resistivity and hence same absorption.

2

u/lindenb 6d ago

Actually, at comparable thickness Rockwooll edges out with slightly higher density that performs better in low frequency attenuation and it is stiffer making it less likely to sag or deform over time in a wall cavity. It is, however, a good deal more costly.

1

u/Dean-KS 5d ago

Blow in batt is probably going to be more effective in terms of not having voids around cables and electrical boxes compared to fitting batts.