How to pass your Sound Testing.
APT has been providing acoustic design and sound testing throughout the UK in places such as Bedford and Bedfordshire, providing you with precompletion sound test reports for your building control officer with a quick and reliable turnaround.    

Good acoustic design for party walls and floors is often critical to achieving building control sign off for Approved Document E of Building Regulations,  yet it is often overlooked in the design stage of the project. To try and negate the chance of precompletion sound test failure, we provide a complete acoustic pathway from the design stage of the project, to the final precompletion sound testing to achieve building control signoff.  approach to acoustic design service, onsite construction checks and sound testing. This ensures your company receives professional advice every step of the way, with an on-going continual consideration of cost.

Our acoustic design and testing service package consists of the following ‘4 step plan’

1. Sample Sound Insulation Testing

We can undertake sample sound testing to the existing buildings walls and floors to check the sound insulation performance of the existing dividing partitions. Thereafter, once the sound levels have been established and targeted acoustic design can be undertaken to ensure compliance with Building Regulations Part E.

• Acoustic Review of the Project. 

We have considerable experience in all matters related to architectural acoustic design and detailing. We can help develop the initial acoustic design of the project from the initial design scheme stage, in particular acoustic isolation, and interior acoustics. We also use the latest Norsonic equipment analysers and sound sources for conventional and binaural acoustic measurements.

• Site Visits

We offer site visits which allow you (the client) and your contractor to feel confident about the outcomes of testing at the end of the build. The site visits let us check that the installation teams are installing the acoustic materials as per manufacturers avoiding crucial onsite mistakes. You can often have a compliant design which still fails due to poor workmanship; the site survey visits negate the risk of sound test failure.

• Precompletion Sound Testing

We undertake the final precompletion testing to ensure compliance with Building Regulations Part E and achieve building control sign off for the acoustic elements of the project. 

We have undertaken hundreds of acoustic design and sound testing packages throughout Bedfordshire and South East, with a 100% pass rate where our acoustic design reports has been implemented.

As we are a multi UKAS accredited testing laboratory, you can be sure our reportage is of the highest standard and will be accepted by the tasked Bedford building control body. As all our testing is carried out in house (we do not subcontract work) which allows us to provide highly competitive pricing whilst maintaining the highest testing standards. It is our ongoing aim to provide a friendly and proactive service from design stage to handover.

If you require acoustic design or sound testing on your Bedford project, please contact us on: 01525 303905, or email us at: info@aptsoundtesting.co.uk or visit our website at www.aptsoundtesting

We cover the following areas throughout Bedfordshire, including Kempston, Wilshamstead, Great Barford, Marston Moretaine, Ampthill, Biggleswade, Flitwick, Newport Pagnell and Woburn Sands 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, please contact us on 01525 303905 or info@aptsoundtesting.co.uk, for more information please visit our website at www.aptsoundtesting.co.uk or download our sound test checklist.

Improving Sound Test Results on Northampton Projects

Our clients often ask us how they can improve the sound insulation on their developments, to pass the sound Insulation testing in compliance with Approved Document E.

One of the main problems is that many dwellings in Northampton, consist of flats converted from large Victorian 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 floor and wall partitions. This can be extremely stressful to the occupant’s well-being is a major cause for concern.

There are some simple 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 its own and you may need to improve the mass and absorption of the partition/s as well.

Improving Existing Party Walls and Floors in Northampton

In our experience after collating the data from hundreds of sound insulation tests in Northampton, refurbishment projects – without any floor upgrades – usually achieve 30-35dB for airborne sound and 70dB for impact Sound.  These figures do not meet the required 43dB & 64dB for a conversion property as stipulated in Part E of Building Regulations. As sound double every 10dB this is classed as a massive failure and acoustic improvements must be made. Many existing constructions consist of a similar floor construction as shown in as detail 1 below.

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. Then, 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. 10-15dB depending on the existing site conditions and quality of the installation. Detail 2 shows this in more detail.

APT Sound Testing Ltd offers a ‘one stop solution’ for all your pre-completion sound testing services in Northampton.

If you have a single dwelling or a site containing hundreds of units, we can help you to achieve compliance and building control sign off. Offering our one stop solution we can minimise your workload by offering a single point of contact throughout the design and construction phase of your Northampton development. We also offer our one stop solution service which encompasses Air Tightness, Sound Insulation and Ventilation Testing in a single package. We can also offer SAP Calculations for domestic properties and SBEMs calculations for commercial properties.

If you would like advice on your acoustic design or require sound insulation testing in Northampton, please contact us now on 01525 303905 or contact us at info@aptsoundtesting.co.uk.

Alternatively for more information, please visit our website at www.aptsoundtesting.co.uk or to help you prepare for your sound insulation test, please download our Sound Test Checklist

Secrets to Successful Sound Testing
There are many considerations to achieving successful sound testing on your development. The main areas that need to be addressed are the dividing wall and flor construction.  When dealing with walls you normally just need to worry about airborne sound; however, with walls it’s both airborne and impact sound which can be far more difficult to deal with.

The usual noise problems associated with airborne sound transmission is TV noise, music and speech. This can be dealt with by applying ceiling treatments as well as mass and isolation to the building components. Impact sound (footfall) performance is increased by the used of resilience layers and isolation of components to prevent noise flanking through the partition.

Airborne Sound Testing
For airborne sound testing Building Regulation Part E requires you achieve at least 45dB for new build properties and 43dB for conversion developments, this applies both to party walls and floors between properties. This level is the difference between the source level and the receiver level during sound testing. Therefore, if the source level in one flat is 110dB and the receiver level in the neighbouring flat is 55dB, the level difference (or sound reduction performance) is 55dB.

The measurement is corrected for several factors such as background noise, room characteristics and frequency weighting, giving the final sound insulation performance value of the tested partition. In this case the higher the number the better the sound insulation performance. The measurement is done by using a Class 1 Analyser and the associated equipment.

Impact Sound Testing
For impact sound testing Building Regulation Part E requires you achieve at least 62dB for new build properties and 64dB for conversion developments. Impact insulation performance only applies to party floors and related to the effectiveness of the floor construction in absorbing shock such as footfall noise. The measurement is done by using a Norsonic tapping machine (as shown below).

The machine has 5 weights which tapping in regular succession on the tested floor which emulates footfall noise. The noise levels are taken in the receiving room below, which are then measured and averaged for different tapper positions, which then gives the sound reduction rating of the floor. In this case the lower the figure, the better the performance.

Good Acoustic Design
To try and ensure you meet the standards stipulated within Building Regulations Part E, careful consideration should be shown to the acoustic design detailing from the stat of the project. offset. Tackling the acoustic design for both new build and conversion project requires two different construction techniques and acoustic design detailing.

With new build properties you have a blank canvas in terms of the overall design whereas with conversions you usually need to work with the existing’ onsite’ construction which can be quite difficult.

We offer an acoustic design package, which contains the following elements:

a.            Sample Sound Testing – of the existing construction. This offers an accurate overview of the acoustic performance of the existing partitions which enables us to offer a targeted acoustic design using the sound insulation performance of the existing construction.

b.            Acoustic Design Review – a full design review of the proposed developments party walls and floors.

c.             Site Survey Visits – to let us view the existing site construction. This allows us to check for potential problematic construction such as inclusion of lightweight blocks in the existing construction. It also lets us check that the installation teams are installing the acoustic materials as per manufacturer’s guidelines.

d.            Final Precompletion Sound Testing in compliance with Building Regulations Part E.

Useful Acoustic Design Considerations

a.            Avoid the use of lightweight blocks in the inner envelope construction and/or stairwell construction etc. as sound will travel both vertically and horizontally from dwelling to dwelling.

b.            The use of resilient suspended ceilings will help improve the performance of the floor partition.

c.             Ensure all support steels/timbers are carefully boxed out where they travel from flat to flat vertically and horizontally.

d.            Use a high quality resilient acoustic membrane on top of the floor to improve the impact performance of a floor.

e.            Ensure all penetrations are fully sealed where they terminate through floors and they are adequately boxed with acoustic quilt and two layers of plasterboard.

In our experience the main 5 considerations when designing for separating walls and floors between dwellings are: If used together or in various combinations they will improve sound insulation properties over a wide range of frequencies.

The main factors are:

a.            Mass

b.            Isolation

c.             Absorption

d.            Resilience

e.            Stiffness

If used together or in various combinations they will improve sound insulation properties over a wide range of frequencies and should achieve compliance with Building Regulations Part E.

Secrets to Successful Sound Testing
In our experience if the acoustic design is taken into consideration from the offset of the project, then it usually results in compliance with Building Regulations Part E.  In Some cases sound test failure can also be down to the poor workmanship rather than the acoustic design that is why we offer a full‘4 step’ acoustic package.

Do you live or operate in Watford, Northampton or Milton Keynes? If you have a project that needs acoustic design advice or sound insulation testing, then please visit the APT Sound Testing website or phone us directly on 07775 623464.

Sound Testing Services in London
The UK capital is a massive city containing in excess of 5 million dwellings, many sharing wall and floor partitions. In this noisy environment it is essential that good acoustic design and construction is incorporated into all new and refurbishment projects along with sound testing for London.

To try and help enforce good acoustic design principles and pre-completion sound testing was introduced in July 2003 to comply with new Approved Document E. The new building regulations required 10% of each party wall/floor construction type to be tested on all new build and conversion properties.

We have undertaken thousands of sound tests on converted properties in London and in our experience if the partitions haven’t received any acoustic upgrades the wall and floor partitions – as per the plate below) normally achieve approx. 30-35dB for airborne sound and 68-74dB for Impact Sound. Obviously these figures fall well short of the required 43dB & 64dB as stipulated in Approved Document E. Also, it’s worth taking into account that sound doubles every 10dB, so 30-35dB for airborne sound and 68-74dB for impact sound would be massive failures and careful acoustic design and construction upgrades would be required.

Detail 1: Existing Floor Partitions (rated at approx. 30-35dB)

Sound Testing Services
Using our many years’ experience in building acoustics, we are able to offer a total design and testing solutions for new and conversion projects. We help many architects and top 10 construction companies with their acoustic design requirements from the largest developments containing hundreds of units through a pair of semi-detached dwellings. We always endeavour to find the most cost effective solution. 

If it’s a conversion project and you are unsure of the floor/wall construction, 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, is consists of at least one airborne and impact test to the proposed dividing floor and an airborne test to the dividing wall. Once the sound test results are established we can then offer a targeted acoustic design solution to achieve a successful sound test in London in compliance with Approve Document E.

Once the construction works are underway we can undertake a site visit to check that the installation teams are installing the acoustic materials as per manufacturer’s guidelines, thus avoiding crucial onsite mistakes during the construction phase. 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 London sound test failure.

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 good acoustic construction; however the partition will still fail as the sound is travelling along a noise flanking path.

We often get asked what ate the main reasons for sound test failures on new and existing dwellings, in our experience they are:

1. 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.
2. Through dividing floors if there is lack of mass or acoustic insulation has not been installed and/or or direct fixing of plasterboard and/or floorboards to joists without using a resilient ceiling construction and/or floating floor.
3. Through Windows if they are no double glazed or have secondary glazing as a minimum
4. Through Fixtures & fittings such as light switches, telephone outlets and TV cable ducts where they sit back to back against the adjoining property.
5. Along structural joints along the perimeter wall and floor joint. These areas should be  filled with acoustic mastic)
6. 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.

There are many quick and simple solutions to improve the acoustic performance of dividing wall partitions. One of the easiest wall solutions is to install a 70mm met-sec partition in front of the existing wall abutting dwellings. Firstly leave approx. 25mm gap between the back of the met-sec and the existing 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. Also make sure that the sockets etc. are placed in a different position to the sockets on the other side of the wall.

To reduce airborne and impact sound transmission through the floor, one simple solution is to add a timber baton to the bottom of the joists. Then add an acoustic resilient hanger.

To the inside of the newly formed void add an AW 25 Isowool acoustic insulation. To the underside of the hangers install 2 x 12.5mm layers of soundboard. Allow for the correct laps in the plasterboard. Add AW100 Isowool to the centre joist void and to the top of the joists install 18mm flooring. To the top of the flooring add a 4mm resilient matt. 

The above Air and Wall solutions should comply with Approved Document Air for you Sound Testing in London. Whatever the problem we can usually find an acoustic solution that will help you achieve Building Regulation compliance.

If you have a project that needs acoustic design advice or needs sound insulation testing then please contact us at info@aptsoundtesting.co.uk or phone us directly on 0203 669 2650 and we should be able to offer you an expedient acoustic solution to help you achieve practical completion.