The quick answer
Floors are almost always an impact noise problem, not an airborne one. Footsteps and dropped objects put energy straight into the structure, and mass alone will not stop that. You need a resilient layer to break the connection between the finished floor and the slab, with MLV for mass and a soft finish on top. Keep the whole build-up off the walls, or it bypasses everything you just installed.
Of all the surfaces in a building, the floor is where the distinction between impact and airborne noise matters most. Voices carried through a floor are a mass problem and respond to a barrier. Footsteps are a structural problem and respond only to isolation. Most floor projects disappoint because they treat the second like the first.
01 /Which noise are you dealing with
| What is heard below | Type | What works |
|---|---|---|
| Footsteps, chairs, dropped objects | Impact | Resilient layer, soft finish |
| Voices, television, music | Airborne | Mass, meaning MLV |
| Both, which is most apartments | Mixed | Full build-up of all three layers |
| Carpet alone over a hard slab | Impact only, partially | Helps the top, ignores the structure |
02 /The build, bottom to top
- Prepare the subfloor. Clean, level and dry. Lift skirting and transition strips so the layers can run to the edges properly.
- Lay the barrier. SoundBlanket MLV directly on the subfloor, seams overlapped and taped. Use 2.5mm at STC 30 for a domestic room, 4mm at STC 34 where the noise below is severe.
- Add the resilient layer. This is the part that addresses impact, by separating the finished floor from the structure. Skip it and you have a heavier floor that still transmits every footstep.
- Finish soft where you can. Acoustic carpet tiles absorb impact at source. Where hardwood or laminate is required, use an acoustic-grade underlay beneath it.
03 /Floating floors, and when they are worth it
A floating floor sits on a resilient layer with no mechanical fixing to the subfloor. It is the most effective domestic approach to impact noise, and it is also the most disruptive and the most expensive in lost floor height. It suits studios, home theatres and gyms. For an ordinary apartment, MLV with a resilient layer and carpet will get most of the way there for a fraction of the cost.
04 /Sometimes the fix is upstairs
If you are hearing footsteps from the flat above, the most effective and cheapest intervention is a rug with a good underlay in that flat, not a ceiling or floor build in yours. It treats the noise at source, before it enters the structure. Worth asking before committing to construction, and worth offering to pay for.
05 /Where this applies
Apartments above occupied units, home studios and theatres, gyms and fitness rooms, offices above retail, and any first-floor room in a house where the room below is used quietly. The principles are the same in all of them, only the thickness of the layers changes.
Related reading: stopping noise from upper floors, and how to soundproof a ceiling.
06 /Frequently asked questions
How do I stop footsteps being heard downstairs?
Footsteps are impact noise going into the structure, so you need isolation rather than mass alone. Lay MLV on the subfloor, add a resilient layer to separate the finished floor from the slab, and finish with acoustic carpet tiles or an acoustic underlay. Keep the whole build-up clear of the walls.
Will carpet on its own be enough?
It helps and it is the cheapest single step, because it softens the impact at source. It will not address airborne noise and it does not isolate the floor from the structure, so on a concrete slab with a real complaint below you will need the full build-up.
What is the most commonly missed detail?
Bridging the floor to the walls. A build-up run tight to the wall or bedded in mortar at the perimeter passes vibration straight into the structure, bypassing the isolation entirely. Leave a perimeter gap, seal it with acoustic sealant, and do not let skirting bridge the joint.
Is a floating floor worth it?
For studios, theatres and gyms, yes. It is the most effective approach to impact noise. For an ordinary apartment it is usually more disruption and lost floor height than the problem justifies, and MLV with a resilient layer and carpet gets most of the way there.
Sonit writes about practical soundproofing for Indian homes and workplaces, with a focus on what delivers measurable results at sensible cost.
