Wednesday 20 September 2017

Architect's clinic: Help! My noisy neighbours are very upsetting — what can I do?

SOFTLY, SOFTLY: If you can isolate the sound from your building’s structure, you will reduce the acoustic transfer. Photo: Eamon Peregrine
SOFTLY, SOFTLY: If you can isolate the sound from your building’s structure, you will reduce the acoustic transfer. Photo: Eamon Peregrine

Eamon Peregrine

Q: I'm on a ground floor apartment. I'm extremely upset by loud footfall from the apartment above me where all floors are timber. The floor is fitted to a 9in mass concrete slab. There is a space of approximately 8in between the slab and my ceiling. The lights are recessed into the ceiling. What can I do to insulate against the noise?

A: I can understand how you would be upset as a constant noise from an adjoining property can really cause distress over a prolonged period and affect the enjoyment of your home.

It is important first to understand how noise travels between different parts of a building.

There are two types of sound involved. The first is airborne sound, ie, sound that travels through the air before reaching a partition - for example, voices, radios, televisions - and impact sound, or sound that is generated on a partition. This is the sound that you are dealing with.

Insulation is the principal method of controlling both airborne sound and impact sound in buildings, and good insulation depends on the general principles of heaviness, flexibility, completeness and isolation.

Although you are dealing with an existing building, there are still a number of things you can do to improve the problem.

These will depend on your budget and on how far you want to go.

The best solution would be to deal with the problem at source. Laying an acoustic matting under the timber floor in the apartment above would isolate the sound from the structure of the building and reduce the transfer to your apartment. With a floated timber floor which did not touch the walls, this would reduce the impact sound being transferred to the concrete floor. The obvious problem with this solution would be that you would need to convince your neighbour to have all their floors lifted to carry out this work.

However, if you are only able to carry out work to your own apartment, then you would need to address the ceiling.

You can do this in two ways. By increasing the mass of the ceiling and by separating the ceiling from the floor structure above.

To increase the mass, you can fill the void above the plasterboard with an acoustic insulation which is denser than a standard thermal insulation.

In order to separate the ceiling, you would need to remove the existing ceiling and install a new suspended ceiling which would be isolated using special resilient bars from the concrete floor above.

The existing plasterboard should be replaced with an acoustic plasterboard or specialist board and separated from adjoining walls. It is important that there are no gaps or holes in this ceiling to reduce airborne sound. If you still wish to install downlighters, then you can obtain special acoustic hoods which will fit over the light fitting within the ceiling void.

Unfortunately, the effectiveness of the works to the ceiling can be greatly offset by flanking noise transfer through the walls of your apartment where they meet the concrete floor above.

It would be advisable to get an acoustic consultant or specialist contractor to advise you on the best solution before getting any expensive and disruptive work carried out, and you also need to consider that as you have become so aware of the noise over time, after completing the work you may still perceive it, even if it has been greatly reduced.

  • If you are considering changes to your home, work with a registered architect. You can find a Registered Architect on riai.ie. The RIAI is the registration body for architects in Ireland.
  • Eamon Peregrine MRIAI is an architect working in Dublin; eamonperegrine.ie

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