How to Soundproof Between Floors in a Flat UK

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

Soundproofing between floors in a flat is one of the most searched acoustic topics in the UK — and for good reason. Whether you're in a Victorian conversion, a 1970s purpose-built block, or a newly converted property, the acoustic performance between floors directly affects quality of life. This guide covers every proven method, with specific advice for UK flat owners and a realistic view of what's achievable.

Why Flat Floors Are Acoustically Challenging

Flats present three specific challenges that detached houses don't have:

1. You share a floor/ceiling structure with another household whose behaviour you cannot control
2. You may not own or have access to the flat above (or below)
3. If the flat is in a converted property (a house split into flats), the original structure was probably not designed for acoustic separation

Under UK Building Regulations Part E, converted flats must meet minimum acoustic standards (DnT,w + Ctr ≥ 45dB airborne, L'nT,w ≤ 62dB impact) when conversion work is carried out. But millions of existing converted flats were built before these standards — and pre-date any acoustic treatment requirement.

Method 1: Treat the Floor Above (Best Option)

The most effective single intervention is adding acoustic underlay under the floor finish in the flat above. This treats impact noise at its source — before the vibration enters the building structure — and delivers the greatest measured benefit.

If you own the flat above, or if your upstairs neighbour is willing:

• Lift the existing floor finish (engineered wood, LVT, laminate)
• Install 6mm Recycled Rubber Acoustic Underlay (74dB ΔLw) across the entire floor
• Re-lay the floor finish as a floating floor (no rigid fixings)
• Result: impact noise reduction of up to 74dB ΔLw at source

The AcoustiLay 8 System takes this further — 12mm combined system delivering 30dB impact + 58dB airborne, addressing both noise types simultaneously.

Method 2: Treat Your Ceiling (When You Can't Access Above)

If you live in the flat below and cannot access the flat above, treating your ceiling is the best option available. A resilient bar system decouples the ceiling plasterboard from the joists above, adding 8–15dB of additional isolation:

• Fix resilient RC bars to existing ceiling joists at 400mm centres
• Infill joist void with 100mm acoustic mineral wool (45–60kg/m³)
• Board with 2 × 15mm acoustic plasterboard
• Seal all perimeter edges with acoustic sealant

This typically adds 8–12dB of impact noise reduction — noticeable but not transformative for severe noise problems.

Method 3: Combined Approach (Maximum Performance)

For a Part E-compliant system, or for serious noise problems, combine both approaches:

• Above: 6mm rubber underlay under floating floor
• Below: Resilient bar ceiling with acoustic mineral wool and double plasterboard
• Joist void: Pack fully with acoustic mineral wool if accessible from above during floor lift

Combined systems in tested configurations achieve DnT,w + Ctr of 50–58dB and L'nT,w of 52–62dB — comfortably meeting Part E and dramatically reducing perceived noise levels.

What About Carpet vs Hard Floor?

Carpet with underlay provides significantly better impact sound reduction than hard floor finishes. If impact noise is your primary concern and aesthetics allow, keeping carpet (with acoustic cork rubber underlay instead of standard carpet underlay) is the simplest upgrade.

If you prefer hard flooring, specify a floating floor over high-performance acoustic underlay — never a glued or nailed-down hard floor directly on a timber joist floor, which performs very poorly acoustically.

Leasehold Considerations

If you own a leasehold flat, check your lease before carrying out significant structural works to the floor or ceiling. Many leases require freeholder consent for structural alterations. Acoustic treatment of the ceiling (adding layers below the existing ceiling) is generally considered a non-structural improvement, but confirm with your freeholder or managing agent.

FAQs

Can I force my upstairs neighbour to soundproof their floor?

Not directly — unless you have a specific lease clause or the noise constitutes statutory nuisance. However, if a flat conversion is being carried out (or has been carried out without Part E compliance), there may be a building control angle. Seek advice from your local authority building control for recent conversions.

How much does it cost to soundproof between floors in a flat?

Material costs for acoustic underlay (treating the floor above): typically £15–40/m² depending on product. Resilient bar ceiling system materials: £25–50/m². A 50m² flat treated with both methods: approximately £2,000–4,500 in materials. Professional installation labour typically adds 50–100% to material costs.

Will I need Building Regs approval to soundproof my flat?

Generally no — improving acoustic performance of an existing flat for your own benefit (not as part of a notifiable conversion) does not typically require Building Regs approval. Check with your local building control if in doubt.