6mm vs 10mm Acoustic Underlay — Which Is Better?

Written by our acoustic insulation specialist — 15+ years experience supplying soundproofing to UK homeowners, developers and contractors. About our experts.

From our acoustic insulation specialist.

In our experience, 6mm is the optimal thickness for most acoustic underlay applications under hard floor finishes — and here is why.

The Performance Difference

Our 6mm rubber underlay achieves 74dB impact noise reduction. A 10mm product typically achieves 20-25dB — significantly less. Why? Because thickness alone does not determine acoustic performance. Density and material structure matter more.

When 10mm Wins

Thicker underlays are beneficial when underfoot comfort is the primary goal — not acoustics. For carpet in a bedroom, 10mm foam feels luxurious. But it will not perform acoustically like our 6mm rubber. Our SilentMat 15mm is the exception — designed for heavy-use areas where both thickness and acoustic performance are required.

Verdict

For acoustic performance: 6mm rubber beats 10mm foam every time. For maximum acoustic performance regardless of thickness: our 12mm acoustic flooring system is the best option available.