Noisy Floors in Flats and Impact Sound
Why hard floors in flats transmit footstep noise to the flat below, and how acoustic underlay helps.
Impact sound — the thud of footsteps, dropped objects or dragged furniture travelling down through a floor into the flat below — is one of the most common sources of neighbour disputes in blocks of flats, and it's very often linked directly to a change of flooring.
Replacing carpet with a hard floor like LVT, laminate or engineered wood without the right acoustic underlay is the single biggest cause, and many leases specifically require a minimum sound rating for exactly this reason.
It's also worth understanding that impact sound and airborne sound are measured and addressed differently: airborne sound (voices, music) is more about wall and floor mass, while impact sound (footsteps, dropped items) is specifically what acoustic underlay is designed to reduce, so the right product needs to be matched to the actual complaint being raised.
Why hard floors transmit more noise
Carpet with underlay naturally absorbs impact noise at the point of contact. Hard floors don't, so unless an acoustic underlay is built in underneath, footstep impact travels efficiently through the floor structure into the ceiling below.
What leases typically require
Many flat leases specify a minimum impact sound reduction rating, often expressed as a decibel figure or an Impact Sound Insulation (ΔLw) value, for any hard flooring installed above ground floor. It's worth checking your lease before fitting, since some buildings will ask for evidence the correct underlay has been used.
How we address it
- Use acoustic underlay rated appropriately for the flooring type and, where relevant, your lease requirement
- Ensure the underlay runs continuously without gaps or compression points
- Isolate the floor from the perimeter walls with an acoustic edge strip where needed
- Provide documentation of the underlay's sound rating if your management company requires it
Diagnosing noise problems in an existing floor
If a floor is already fitted and generating complaints, we check what underlay (if any) was used, whether it's compressed or degraded, and whether the flooring is isolated from the surrounding walls and skirting, since sound can bridge through a floor that's rigidly connected to the wall structure.
Table: flooring change and typical impact
| Change | Typical impact sound outcome |
|---|---|
| Carpet to LVT, no acoustic underlay | Noticeable increase in impact noise |
| Carpet to LVT, correct acoustic underlay | Minimal increase, often lease-compliant |
| Old worn carpet underlay | Impact noise increases as underlay compresses over time |
Getting it right from the outset
The most cost-effective way to avoid a noise complaint is specifying the correct acoustic underlay at the point of fitting, rather than retrofitting a solution once a neighbour has already complained. We factor lease requirements into the specification whenever we're fitting hard flooring in a flat.
What to do if a complaint has already been raised
If a downstairs neighbour or management company has already raised a noise concern, it's worth getting the existing underlay checked before assuming the whole floor needs relaying, since in some cases only sections of a floor — such as a hallway directly above a bedroom — are the real source of the complaint.
We can survey an existing installation, identify whether underlay is missing, compressed or simply the wrong specification, and advise on the most cost-effective way to resolve the issue, which isn't always a full re-lay of every room.
Frequently asked questions
- Does my flat lease really require special underlay?
- Many do, particularly for hard flooring above ground floor. It's worth checking your lease or asking your management company before fitting, and we're happy to help interpret what's required.
- Can acoustic underlay be added to an existing hard floor?
- Not without lifting the floor and relaying it, since the underlay sits beneath the flooring itself. If noise is an ongoing issue, this is usually the only real fix.
- Is carpet always quieter than LVT or laminate?
- Generally yes for impact sound, though a hard floor over the correct acoustic underlay can perform close to carpet levels, which is why underlay choice matters so much.
- Can you provide proof of the underlay's sound rating for my management company?
- Yes, we can supply manufacturer's technical data for the acoustic underlay used, which is often what's requested for lease compliance.
Keep reading
Why timber floorboards squeak or feel uneven underfoot, and how we sort it before new flooring goes down.
What it means when our survey uncovers a damp or uneven subfloor, and how we prepare it properly.
How to tell whether a tired, stained carpet can be professionally cleaned or genuinely needs replacing.
See how we survey, prepare and fit LVT across Kent.
See how we survey, prepare and fit laminate across Kent.
Talk it through with a fitter, not a call centre
Book a free, no-obligation survey with Kent Flooring Warehouse's in-house fitting team — call 07702 737267 and we'll inspect the floor and give you a straight answer on the fix.