Acoustilay 15

Our go-to acoustic underlay for carpet. If footsteps, voices or the TV are coming through your floor, Acoustilay 15 is the answer we reach for first. It's the heaviest grade of the UK's original high-mass acoustic underlay: lay it under your carpet and it cuts impact noise, like footsteps and dropped items, and at 15kg/m² it also reduces airborne noise, like voices, TV and music, through timber floors.

See the complete Acoustilay carpet systemEvery layer explained, plus a video showing how it goes down.Watch the video

Swapping carpet for a hard floor in a flat?

It's one of the most common causes of neighbour complaints we hear about. Carpet and underlay soak up a lot of footfall, so when they come up and wood or laminate goes down, every footstep, chair scrape and dropped item travels straight into the flat below. That's why so many leases, particularly in London, require proper acoustic treatment before you change a floor finish, and why Acoustilay is the product they so often name.

Acoustilay 15 bonded to the floor with an Acoustilay MDF overlay on top gives you a solid, stable base for laminate or engineered wood, with the acoustic performance your neighbours, managing agent and lease expect.

Why choose Acoustilay 15?

• Made for carpet: it loose-lays straight over your floor, with Acoustilay Perimeter Strip carrying the gripper rod. No adhesive needed for a standard carpet install.
• Tackles both types of noise: 48dB L'nT,w impact and 57dB DnT,w + Ctr airborne, beating the Part E targets for both.
• Only 15mm thick: a slim build-up that keeps door and threshold changes to a minimum.
• Timber or concrete: on a concrete floor it delivers a tested 42dB improvement in impact sound.
• The trusted choice for flats: many leases, particularly in London, specify Acoustilay when you swap carpet for a hard floor.
• Made in Britain: 100% UK sourced and manufactured, and trusted for over 30 years.

Everything you need

Complete your floor in one order. Tap + Add to drop each item straight into your basket.

Essential for carpet

Acoustilay Perimeter Strip 15

Seals the edge and carries your gripper rod. 1.2m per strip.

£9.00+ Add

Hard floors & stairs

Acoustilay Adhesive 5L

Bonds Acoustilay to the floor and MDF to Acoustilay. Around 15m² per tub per layer.

£48.00+ Add

Hard floors

Acoustilay MDF 6mm

A stable deck for laminate, engineered wood, carpet tile and bonded carpet. 1.44m² per board.

£33.00+ Add

MDF joints

dB Panel Adhesive

PVA for the MDF tongue and groove joints. 1L covers around 20m².

£10.90+ Add

How much do I need?

Each sheet covers 1.44m², so allow 0.7 sheets per m² plus around 10% for cutting. Perimeter strips are 1.2m long, so divide your room perimeter by 1.2. For example, a 3.2 x 3.2m bedroom (about 10m²) needs 8 sheets and 11 perimeter strips. Not sure? Call us on 01928 571 856 and we'll work it out with you.

Fitting under carpet

1. Make sure the floor is level, clean and dry, and let the Acoustilay acclimatise to the room.
2. Fix Acoustilay Perimeter Strip around the room, barrier layer down, with the acoustic seal pressed against the wall or skirting.
3. Nail your gripper rods on top of the perimeter strip.
4. Loose-lay the Acoustilay sheets in a brick-bond pattern, butted tightly to the strip and to each other. Avoid any gaps.
5. Fit your carpet as normal. Nothing should be fixed through the Acoustilay.

Other floor finishes

• Laminate, carpet tile and bonded carpet: bond Acoustilay to the floor with Acoustilay Adhesive, then bond Acoustilay MDF 6mm on top. Glue the MDF joints with PVA, keep them 50mm away from Acoustilay joints, and leave a 5 to 10mm sealed gap at the walls.
• Engineered wood: the manufacturer allows it directly on top in homes, but from experience we recommend the MDF overlay for a flatter, longer-lasting floor.
• Offices, schools and other commercial spaces: always add the MDF overlay, whatever the finish, to protect against wheeled furniture and heavy traffic.
• Ceramic and stone tiles: not suitable. Ask us about Acoustilay Tilemat instead.

Stairs and fitted units

On stairs, bond Acoustilay to each tread and riser with Acoustilay Adhesive, fit perimeter strips to the tread or riser, and add an MDF fillet under the nosing for an even height. For kitchen or bathroom units, fix them to an MDF plinth the same height as the Acoustilay rather than through it, and treat the floor inside fitted wardrobes too.

Meeting Part E

For new-build flats, Part E requires separating floors to achieve no more than 62dB L'nT,w for impact sound and at least 45dB DnT,w + Ctr for airborne sound. For conversions it's 64dB and 43dB. Acoustilay 15's tested results of 48dB and 57dB beat both.

Failed a sound test? See how Acoustilay 15 turned a fail into a pass in our sound test case study, or read what makes Acoustilay so good.

Technical specification

Full test details are in the Acoustilay datasheet under Technical Data.