Rubber acoustic underlay: choosing the right construction

Rubber underlay appears beneath very different floors, from bonded timber to tiles and carpet. The material name alone does not tell you which construction it suits.

Compare the permitted floor finish, support characteristics and installation detail alongside the acoustic report. A compact system that fits the threshold may be more practical than a thicker option, provided the complete floor meets the project’s requirements.

What is rubber acoustic underlay made of?

The rubber underlays in this guide are recycled rubber granules held together with a polyurethane (PU) binder. Some makers add cork.

• Recycled rubber only. REGUPOL sonus core is made from end-of-life tyres bound with polyurethane (sonus core 5). DAMTEC Multi and DAMTEC Rubber, ImpactaMat and Vibramat are also recycled rubber with a binder.
• Rubber and cork. DAMTEC Standard mixes rubber and cork granules (KRAIBURG data sheet). REGUPOL sonus eco 5 is tyre rubber and cork (sonus eco 5). Dunlop Advantage 3 is 85% recycled rubber and 15% natural cork (Dunlop).

REGUPOL sonus multi is a different kind of mat: PU foam and cork, not rubber. We cover it in Regupol vs Damtec.

Which thickness should you choose: 3, 5, 6 or 10 mm?

Start with the floor you are putting on top, then look for a test of that floor. ΔLw is the laboratory improvement over a bare slab, so higher is better. Ln,w is the laboratory result for the whole floor, so lower is better.

Sources: Damtec’s direct-stick timber, carpet, tiling, floating timber and under-screed brochures (140 mm slab, no ceiling), and REGUPOL’s sonus core 5, sonus core 10-S, sonus eco 5 and sonus curve 6 pages.

Three things stand out:

1. Thicker is not always better. Under 14 mm engineered timber, REGUPOL’s 5 mm and 10 mm mats both gave ΔLw 18 dB. Under tile, Damtec’s 2 mm mat gave 18 dB and its 3 mm mat gave 17 dB. Under glued parquetry, its 3 mm and 5 mm mats both gave 18 dB.
2. The floor on top changes the result more. The same 2 mm Damtec thickness gave 28 dB under carpet and 18 dB under tile.
3. Screeds benefit from thickness. Under a tiled screed, REGUPOL’s mats went from 21 dB at 5 mm to 23 dB at 10 mm, and the 6 mm profiled mat gave 24 dB.

Two more rubber products publish field results rather than laboratory ones. Embelton tested 5 mm ImpactaMat at 800 kg/m³ under bonded ceramic tile on a 150 mm slab with no ceiling, and reports a 20 dB improvement over the bare slab (LnT,w + CI 56). The Vibramat 5 mm data sheet (700 kg/m³, December 2025) reports on-site reductions of 16 to 17 dB in LnT,w against the untreated slab, across several projects with tile and engineered timber. Field and laboratory numbers are not directly comparable. Our guide to acoustic ratings explained shows why.

Some rubber underlays sold through hardware stores, such as the Ultimate Flooring rubber acoustic underlay, did not have a maker’s data sheet we could open. For any product, ask for the full test report before you buy.

How does rubber compare with EVA, foam and cork underlay?

Foam. Dunlop’s thin foam underlays for floating floors, such as Timbermate (2 mm) and Aquacoustic (3 mm), are polyethylene foam with a moisture barrier, recommended for laminate and engineered timber floating floors (Dunlop). For tiles and screeds, the systems in this guide use dense rubber or rubber and cork mats instead. For floating timber, see acoustic underlay for timber floors.

EVA. EVA foam underlays are sold in Australia, but we did not find a maker’s data sheet with a laboratory ΔLw and a stated build-up that we could check. Ask for one before you compare it with rubber.

Cork. Forbo’s Corkment is a 2 mm cork-based underlay for Marmoleum linoleum. Forbo gives an impact sound reduction of 14 dB with 2.5 mm Marmoleum sheet, to EN ISO 717-2. Cork is also mixed into several rubber products listed above.

Vinyl. Damtec says recycled tyre rubber can cause plasticiser migration into vinyl, and it sells DAMTEC Resilient, a PU foam and cork underlay, for sheet vinyl and LVT instead (Damtec LVT page). KRAIBURG recommends a separating layer under elastic flooring.

Does rubber underlay flatten over time?

Makers say it holds up, but few publish a figure you can compare. Embelton gives ImpactaMat a compression recovery of “90% minimum at 1 hour” and a recommended long-term loading maximum of 15% strain (ImpactaMat brochure). REGUPOL gives sonus core 5 a compressibility of 0.5 mm or less and a maximum traffic load of 60 kN/m² (sonus core 5).

We did not find a compression set result to a named standard for any of these products. Treat claims such as “will not compress” as the maker’s view.

Commercial and gym floors

Gyms need more than an underlay. REGUPOL’s sonusfit m 517 is a 48 mm or 88 mm gym floor system; REGUPOL reports a ΔLw of 28 dB (48 mm) and 29 dB (88 mm) on a solid reference ceiling, tested to DIN EN ISO 10140 (sonusfit m 517). The older Regupol 4080 appears in a 2015 Regupol gym sheet as an underlay glued under 8 to 12 mm rubber gym flooring, but it is not on REGUPOL Australia’s current acoustic product pages. For a gym in a mixed-use building, ask an acoustic consultant to design the floor.

How much does rubber acoustic underlay cost?

Most makers do not publish prices. Embelton does. As displayed on its ImpactaMat page on 25 September 2026, a 1150 x 1150 mm sheet cost $14.85 at 3 mm and $19.80 at 5 mm, including GST, with delivery from $30. REGUPOL Australia and Damtec Australasia do not list prices on their websites. For anything else, get three quotes that name the product, thickness and adhesive.

What to check on a rubber underlay data sheet

• A test with your floor type on top, and the report number
• Slab thickness and whether a ceiling was present
• Lab (ΔLw, Ln,w) or field (LnT,w) result
• Density and thickness tolerance
• Whether it can be glued, loose laid or both, and the approved adhesive
• Any warning about vinyl or plasticiser migration
• Moisture advice for wet areas, and the warranty terms

Join the waitlist below to hear when