Sound insulation

There are many situations where poor sound insulation is a contributing factor towards the cause of noise disturbance between adjoining properties.

The standards for sound insulation have gradually improved since 1976 through the Building Regulations. If you have any queries regarding the standard of sound insulation that is likely to be relevant to your property then please contact the Building Control Section on 01256 844844 or National House Building Council (NHBC) on 0870 2414306. The regulations are not retrospective so there is no obligation on any individual, including the owner, to carry out works to upgrade the sound insulation of a property.

Since the House of Lords decision in London Borough of Southwark v Mills & Others and Baxter v London Borough of Camden, it has not been possible to use the nuisance provisions of the Environmental Protection Act 1990 to deal with inadequate sound insulation between dwellings.

If you decide to carry out sound insulation works it is important to be aware that if your property is physically attached to another you will always to some extent be able to hear your neighbours and be aware of some of their activities.

The provision of sound insulation may not make high noise levels within your neighbour's property inaudible or even acceptable within your home. At best it will only reduce the noise you are hearing. It is important therefore not to have an unrealistically high expectation of the improvement that will be achieved. However, if you properly install the appropriate amount of insulation you should note an appreciable improvement.

Sound insulation methods

In recent years many proprietary sound insulation systems have been marketed. All the systems are essentially similar in technology.

Floors

Floor treatments have an absorption layer laid on the existing floor, with high density boarding on top creating the new floor. The depth of the absorption layer and boarding usually governs the amount of sound insulation provided.

Special edge treatments create a seal between the new floor and the skirting boards.

Some systems recommend the installation of mineral wool fibre in the void between the joists (i.e. between your neighbours ceiling and your existing floor). The systems are generally 15mm to 50mm thick so room height will be lost.

To reduce flanking transmission it is recommended that the whole floor of the property is treated. Door clearances will need to be checked and sockets may need to be repositioned.

Please read our leaflet on Noise Associated with Laminate Flooring if you are considering installing such flooring.

Ceilings

Sound insulation systems to treat ceilings are usually about 115mm deep so generally require a relatively high ceiling height to make them viable. They provide a new ceiling acoustically independent of the existing one with an absorption layer in between.

It is important that no holes are made in the new ceiling that would compromise its acoustic integrity.

Walls

A new wall, acoustically independent of the existing one is provided. It is usual for the system to be about 60mm deep, so the reduction in room width will be a consideration. Wall sockets should be surface mounted as not to affect the new walls acoustic integrity. Instead of proprietary systems it is possible to construct DIY sound insulation systems. These rely on the same principles of constructing a new floor, ceiling or wall acoustically independent of the existing one but using traditional building techniques. While DIY systems are generally cheaper, proprietary systems benefit from having a known acoustic performance (provided manufacturer’s installation instructions are followed). For DIY installations you should have a basic understanding of noise control and be meticulous in your work to ensure optimum performance is achieved from the materials.

Sound insulation works can be costly and disruptive. The type of system installed will often be a compromise between cost, height/space restrictions and the degree of insulation required. Before commissioning works you will need to have a realistic approach to the cost/benefit of installation, balanced against the degree of disturbance you are experiencing from your neighbours