Sound Insulation Testing to Party Walls and Floors
There are many ways to improve party walls and floors to pass sound insulation testing for Approved Document E. Some improvements may be as simple as installing silent closure mechanisms on kitchen cupboards and bedroom wardrobes. If sockets are installed back to back in separating walls may also lead to complaints about noise when plugs are inserted and switches are activated, as the wall will be weakened in this area. The use of an additional sacrificial wall lining can reduce such noise complaints.
Many newly formed dwellings consist of flats converted from large Victorian/Edwardian houses. Unfortunately at the time of the building conversion, designing for sound insulation was not a high priority and so many of the dwellings suffer from adverse noise transference between the party floor and wall partitions. This can be extremely stressful to the occupant’s well being and can lead to excess stress.
There are ways to improve the airborne and impact performance by improving the wall/floor partitions ability to reduce the amount of sound transmission from one side of a construction element to the other. By isolating the different materials may not be enough it’s own and you may need to improve the mass of the partition as well.
Improving Existing Floor Partitions
In our experience refurbishment projects usually achieve 30-35dB for airborne sound and 70dB for Impact Sound, if no previous acoustic upgrades have been made to the existing construction. Unfortunately these figures fall far short of the required 43dB (for airborne sound) & 64dB (for impact sound) as stipulated in Part E of Building Regulations. As sound levels double approx. every 10dB, so if a partition failes by 10dB it is a massive failure and subsequent acoustic improvements must be made to avoid potential future complaints.
Improving Floor Partitions
To reduce airborne and impact sound transmission this usually means adding density and isolation to the floor construction. This can be as simple as adding a drop ceiling consisting of 125mm timber frame. The top of the frame must be a minimum of 25mm below the existing ceiling finish – such as lathe and plaster. To the inside of the timber frame add 100mm of Acoustic Wool and two layers of sound-board tacked to the bottom of the timber frame – all boards to be lapped. This should improve your sound test results by approx. 15dB depending on the existing site conditions and quality of the installation.
The standard onsite construction for existing internal walls may be a mixture of 100mm masonry with render applied to either side; or, 100mm timber partition with lathe and plaster to either side. Unfortunately neither of these existing wall constructions will have the acoustic properties to pass Part E in their existing state due to lack of mass, absorption and poor isolation values.
Acoustic Upgrade for Wall Partitions
One way to quick and simple way improve the acoustic performance of a the dividing wall partition, is to install a 70mm met-sec partition in front of the existing wall – its usually best to install this within the largest room. Leave approx. 25mm gap between the back of the met-sec and the wall. Then install 50mm acoustic wool to the inside of the met-sec and add two layers of soundboard to the outside of the met-sec frame, ensuring all boards are properly lapped and the perimeter joints are filled with acoustic mastic.
If you would like more information in regards our acoustic design service or sound testing service sound testing, please contact us at: info@aptsoundtesting.co.uk or call Darren Direct on 07775623464.
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Alternately, If you would like more information on how to prepare for your sound testing please download our sound test checklist.