Acoustic insulation explained: stopping noise between rooms

How sound travels

Sound moves through air and through structures. Inside walls, the empty cavity acts like a drum, amplifying noise between rooms. Filling that cavity with dense insulation absorbs sound energy before it reaches the other side.

Rw and STC ratings

Wall systems are rated using Rw (weighted sound reduction). Higher numbers mean better sound isolation. Adding acoustic batts to a standard plasterboard wall can raise its rating by several points — a noticeable difference to the ear.

Why density matters

Acoustic batts are denser than standard thermal batts. HD Acoustic Partition Batts are designed specifically for internal walls, giving more mass to absorb mid and high frequency noise such as voices and TVs.

Best practice

Fill the full cavity without compressing the batts, seal gaps around power points and penetrations, and consider double plasterboard or resilient mounts for bedrooms, home theatres and media rooms.

For noisy pipes, SoundLag™ Pipe Lagging wraps around waste pipes to reduce rushing water noise.