We have undertaken hundreds of sound insulation tests on converted properties throughout London and Greater London, and in our experience if the floor partition haven’t received any acoustic upgrades – as shown in the image below, they usually achieve approximately 30-35dB for airborne sound and 66-74dB for Impact Sound. Obviously, these figures fall well short of the minimum requirements of Approved Document E, which requires 43dB & 64dB.
Our Acoustic Design & Testing Solution in London
Using our many years of experience in building acoustics, we can offer a total acoustic party walls and floor design and testing solution for new and conversion projects. We have previously helped many architect and developers with their acoustic design and testing requirements on projects containing hundreds of units, through to a pair of semi-detached dwellings. Using our experience and knowledge, we always try to provide the best solution considering material costs and on-site buildability.
If it is a conversion project and you are unsure of the existing floor construction and sound insulation performance, we often recommend our ‘sample sound testing service. Firstly, we visit site and undertake sample sound testing to at least one floor and wall partition – this usually consists of at least one airborne and impact test to party floor. Once the airborne floor sound test results are established, we can then offer a targeted acoustic design solution achieve compliance with Approved Document E.
An acoustic review makes up the 2nd part of our acoustic service. Using the data collected from the sample sound insulation testing we can undertake a targeted acoustic review. We always try to provide an acoustic solution that considers material cost and onsite buildability. We will try to ensure that its an off the peg solution, so that there no further delays and downtime are caused by material deliveries.
The 3rd part of our acoustic service is the undertaking of site visits. We use the site visit to check that the construction team is installing the acoustic materials in-line with manufacturer’s guidelines. In our experience a sound test failure is often caused by poor workmanship rather than the actual acoustic design. The site survey helps to further reduce the chance of a test failure.
The last part of our acoustic service is the pre-completion sound testing. We visit site and undertake the post-completion sound testing to demonstrate compliance with the acoustic performance requirements of Approved Document E. this allows our clients to attain building control signoff for the acoustic portion of their projects.
The pitfalls of noise flanking in London
Sometimes, there are more technical issues such as noise flanking which may require more detailed diagnosis and invasive investigation, such as the removal of some of the wall and floor partitions. In many cases a large amount of noise flanking is due to serious design faults, e.g. the use of lightweight blocks in the construction of the walls in an apartment development. This allows the sound to travel along the walls and floors from dwelling to dwelling. In many cases a wall and/or floor partition may have a very robust acoustic construction within the party floor construction; however, the partition will still fail as the sound is travelling up and down the walls via a noise flanking pathway.
Typical reasons for a failed sound testing through party floors in London
Where lightweight blocks used in the inner envelope construction. This allows sound to travel along the lightweight blocks both vertically and horizontally from dwelling to dwelling.
a. Bridging an acoustic floor system with skirting, or via screwing down the floor system to the joists.
b. Resilient bars missing or fitted incorrectly to the underside of the floor joists.
c. Excess recessed lights have been fitted into an acoustic ceiling.
d. The dividing floor has a lack of mass or acoustic insulation has not been installed correctly, and/or or direct fixing of plasterboard and/or floorboards to joists without using a resilient ceiling construction and/or floating floor.
e. Through Windows if they are not double-glazed units and/or have secondary glazing as a minimum – this is often a problem if there is a continuous curtain wall running through the dwellings.
f. Along structural joints along the perimeter wall and floor joint. These areas should be filled with acoustic mastic)
g. Structural steels that run through one property to the other without material isolation, i.e. plasterboard is screwed directly to the steel offering little or no noise isolation.
Simple Acoustic Upgrades to help pass your sound testing in London
There are many quick and simple solutions to improve the acoustic performance of dividing floor partitions. One of the easiest floor solutions is to retain the existing joists, between the joists install a 100mm RW45 acoustic insulation. Above the joists install 22mm T&G boarding with a layer of 6mm resilient membrane to the top of the board – this must be bonded to the floor. This can then be finished with engineered flooring and/or carpet. Below the joists install resilient bars and below the bars install 1x15mm & 1×12.5mm layers of soundboard. All boards must be properly lapped, and the perimeter joints filled with acoustic mastic.
How APT Sound Testing can help
It can be very time-consuming trying to identify the cause of a failed sound test. Therefore, it is always best to hire an experienced consultant. APTs acoustic consultants have years of experience and will advise you on the best course of action to rectify any problems.
We are also a UKAS accredited company, so you can be sure of a friendly and professional service providing a ‘one stop’ solution for all your acoustic requirements.
APT can advise on all types of acoustic design to help you pass your sound testing to party walls in flats, whether it is accomplished during initial construction or during a refurbishment or renovation project. Whatever the problem we can usually find an acoustic solution that will help you achieve Building Regulation compliance.
We cover the following areas throughout London and Greater London, including the boroughs of City of London, Barking and Dagenham, Barnet, Bexley, Brent, Bromley, Camden, Croydon, Ealing, Enfield, Greenwich, Hackney, Hammersmith and Fulham, Haringey, Harrow, Havering, Hillingdon, Hounslow, Islington, Kensington and Chelsea, Kingston upon Thames, Lambeth, Lewisham, Merton, Newham, Redbridge, Richmond upon Thames, Southwark, Sutton, Tower Hamlets, Waltham Forest, Wandsworth, Westminster to help you achieve the requirements of Approved Document E and attain building control signoff.
If you would like more information in regards to sound testing service and/or acoustic design services in Hertfordshire, please contact us on 01525 303905 or firstname.lastname@example.org, for more information please visit our website at www.aptsoundtesting.co.uk or download our sound test checklist.