Why floating floors exist
Impact energy — a barbell drop, footfall, a kick drum — is injected directly into the slab and re-radiates as noise in rooms far from the source. Adding mass or absorption to the room below does very little. A floating floor decouples the walking surface from the structure through an isolation layer, so far less energy enters the slab in the first place.
Natural frequency is the selection criterion
An isolation system only attenuates above roughly 1.4 times its natural frequency. Below that it can amplify. Select the isolator so the system's natural frequency sits well below the lowest frequency you need to control.
| Isolator type | Typical natural frequency | Suits |
|---|---|---|
| Rubber / EPDM mat underlayment | 18–25 Hz | Footfall, light gym, residential |
| Moulded rubber pucks or pads | 10–18 Hz | Commercial gyms, dance studios |
| Spring isolators (jack-up floors) | 4–8 Hz | Recording studios, cinemas, nightclubs, plant rooms |
A typical six-layer studio build-up
- 1. Structural slab, cleaned and levelled
- 2. Spring or rubber isolators on a designed grid, sized to the loaded weight per point
- 3. Perimeter isolation strip — the floating slab must not touch any wall or column
- 4. Formwork deck and reinforcement
- 5. Floating concrete slab, typically 100–150 mm, or a dry mass build-up where load is limited
- 6. Finish: screed, timber or sports surface
Detailing that decides success or failure
- One rigid contact — a screw, a pipe clamp, a splash of mortar at the perimeter — short-circuits the entire system
- Every service crossing the floating slab needs a flexible connector or isolated sleeve
- Skirtings must be fixed to the floating slab and sealed with a flexible joint to the wall, never fixed to both
- Verify loaded deflection against the design after pour; unequal loading changes the natural frequency
- Coordinate slab depth and dead load with the structural engineer at concept stage, not after the layout is fixed
Where a simpler solution is enough
Not every project needs a jack-up floor. For an office above a light gym, a high-quality 15–25 mm rubber mat under a screed may deliver the required improvement at a fraction of the cost and build-up height. Match the system to the measured or predicted source spectrum rather than defaulting to the heaviest option.
Frequently asked questions
How thick is a floating floor system?
Mat-based systems add roughly 30–60 mm including screed. Spring-isolated concrete floating floors typically add 200–350 mm once the isolation void, slab and finish are included, so the void must be planned early with the structural team.
Will a floating floor stop gym noise in the apartment below?
It is the most effective single measure for weight drops and footfall. For heavy free-weight areas, combine the floating floor with a dedicated drop-zone platform and an isolated ceiling below for the best result.
Rubber or springs — which should I choose?
Rubber suits mid- and high-frequency impact and lighter loads. Springs are required when low-frequency energy matters — bass in studios and clubs, or plant rooms — because only springs reach the 4–8 Hz natural frequency range.
Floating Floor Systems
Rubber, spring and HD isolation floors for studios & plants.
View Floating Floor Systems