Soundproofing an apartment from neighbours: floor, ceiling and walls

How do you remove the sound of a neighbour's footsteps above?

Footsteps are best stopped where they are born: a resilient layer under the neighbour's floor. If that is not possible, a ceiling on resilient hangers with mineral wool and two layers of plasterboard helps. It cuts impact noise noticeably, but not entirely: part of the sound travels through walls and structural elements.

That is why one ceiling rarely solves the problem. In old Barcelona buildings the floors are light: timber or steel beams with a brick vault, and sound travels easily through such a structure. Spain's CTE DB-HR, for new buildings, requires impact noise between different dwellings not to exceed 65 dB in L'nT,w and airborne insulation to be at least 50 dBA. Old buildings usually do not reach those values, and they can serve as a target for the result.

How is a ceiling on resilient hangers built and how much height does it cost?

The ceiling hangs from resilient mounts that decouple it from the floor above: sound does not pass through the fixings. In the cavity, at least 10 cm deep, 50 mm mineral wool is placed and below it two layers of 15 mm plasterboard.

The height loss is roughly 10 to 15 cm. In an Eixample flat with 3.2 to 3.5 m ceilings it is acceptable; with 2.5 to 2.6 m you must choose where to drop the ceiling and where to leave it. The same cavities are handy for hiding ducted air conditioning and service routes, so the ceiling is planned with them. Hangers and boards must not be short-circuited with rigid rods: one forgotten rigid fixing brings the effect to zero.

Around the perimeter it is separated from partitions by resilient tape, and lights and grilles are sealed, or sound finds the gaps.

What does a floating floor give and how much height does it take?

A floating floor is a screed on a resilient layer that does not touch the walls. A 10 to 20 mm layer damps impact noise, a 5 to 6 cm screed adds mass and a perimeter strip runs round the edge. In total the floor rises 7 to 9 cm, and that is allowed for at junctions with stairs, doors and adjoining rooms.

It is the best way to reduce the noise of your own footsteps for the neighbours below. It also helps against footsteps from above: less secondary noise comes through the walls. A floating floor must have no rigid bridges through walls, pipes and skirtings, so skirtings sit on a resilient gasket and pipes are wrapped.

On a historic floor the screed load is checked by the structural engineer: old beams may not take an extra 100 to 120 kg per square metre.

How are box-in-box wall linings made and what do they cost in space?

A wall lining is a frame on an independent structure that does not touch the wall, with mineral wool inside and two layers of plasterboard outside. The frame sits on resilient tape and is not rigidly fixed to the wall, or sound would travel through the fixings.

The loss of floor area is 6 to 10 cm per wall. In a 4 by 5 m room that is 1 to 1.5 m2 across the whole perimeter, so the box is built where quiet is needed: in the bedroom and in a study beside noisy neighbours. The ideal is to solve ceiling, floor and walls together, as a room within a room. Then noise does not bypass one element through another.

Penetrations are checked: every socket, pipe and duct pierces the envelope and needs sealing. Such details take half the effect.

Does it help against street noise and is it needed under parquet?

Against street noise, windows do the work, not walls. In Barcelona laminated acoustic glass (for example 6+6 or 44.2 with an interlayer) and an airtight frame protect well. Ventilation is solved separately: an open gap cancels the effect, so heat recovery or acoustic air vents are fitted.

As for parquet, glued onto an old screed it barely reduces impact noise. Floating parquet on a resilient underlay does, but the underlay must be certified for noise reduction and is chosen together with the finish. More on choosing a floor is in our article on how to choose flooring.

Doors count too: a leaf without seals lets sound through like a hole. For a bedroom choose a door with a perimeter seal and a threshold.

What about the neighbours and the comunidad when soundproofing?

Soundproofing inside your flat does not require the neighbours' consent, but work on the ceiling and floor structure is discussed with the technician, because loads and structural changes are part of the design. It often pays to talk to the neighbour above: a resilient layer under their floor solves it better than any structure of yours.

Before starting, check what the statutes and comunidad rules say about hours for noisy works, and warn the neighbours. If the building is protected, floors and vaults are kept at the authority's insistence and the solution moves into your box with minimal intervention. There is an article on protected buildings.

The operating rule for the ceiling and floor is simple: do not nail through the envelope and do not hang weight from plasterboard without anchors to the frame.

How can BCN YARD help with soundproofing a flat?

We visit the flat, check floors and ceilings and propose a solution that does not eat extra height. Ceilings, floors and walls are planned together with the services so nothing is opened twice. We work with our own crew and trusted subcontractors, one person is responsible for the site, and we speak Russian and Spanish. The estimate is prepared after the visit and measurements.