UKAS Accredited Air & Sound Testing Laboratory

APT Sound Testing is UKAS accredited for both sound insulation testing and air tightness testing. Being a UKAS accredited laboratory for air and sound testing, provides an assurance of the competence, impartiality and integrity of the testing body. UKAS accredited testing reduces the need for testing company to be assessed by each of their customers.

UKAS’ involvement in international groups such as EA, IAF and ILAC, provides for mutual recognition. This reduces the need for multiple assessments of suppliers, and as a consequence helps to reduce barriers for testing companies that have UKAS accreditation.

Most businesses – big or small within the industry they operate in, require some form of certification. This is the ultimate mark of quality and professionalism within their sector. With so many types of accreditation to choose from nowadays, it can be difficult to know what type would be best for your company. One place to start is by making sure that the testing consultancy you use is UKAS accredited. This is something you simply cannot afford to overlook.

What is UKAS accreditation?

UKAS stands for the United Kingdom Accreditation Service. It is the only government recognised national accreditation body in Britain. It has been designed to evaluate the competence of all organisations that supply services relating to certification, calibration, inspection, and testing. If a certification body meets their standards, they will then be accredited. If an organisation has reached this status, it means that they have the ability to deliver results while being reliable, impartial, and competent. Therefore, if you choose a UKAS accredited certification body, you can be certain of the highest levels of quality. APT Sound Testing is UKAS accredited for both sound insulation testing and air tightness testing, so you can be sure of the highest quality testing services and reportage at all times.

Why are not all companies UKAS accredited?

Unlike many other certification bodies, UKAS is a non-profit organisation, meaning their sole purpose is to ensure that companies are regulated properly and high standards are achieved at all times. This offers customers ultimate peace of mind. Other companies that don’t have UKAS certification, may have lower prices in some instances as they are not bound by the more stricter guidelines put in place by the United Kingdom Accreditation Service. If the company you are using is not UKAS accredited it may mean that you are taking a massive risk, as the quality of product testing and auditing quality may vary. If the company you are using for your air tightness and/or sound testing has not sought UKAS certification, it can be a good indicator that the quality may be lower.

Why it’s important to be UKAS accredited

There are also a lot of non-accredited air and sound testing companies that offer their service on a no certificate no fee basis; however, although this may seem great on the surface it usually means is that a certificate is barely ever refused. This does not say a lot for the quality of the testing company if they are simply allowing anyone to achieve their certification. It goes completely against the international standard that UKAS adheres to. Also, their accreditation isn’t worth much when you consider that they do not have to adhere to any regulatory constraints, and thus they offer little assurance in terms of accountability, impartiality, or integrity. Hats why it’s really important to use UKAS accredited testing laboratories like APT Sound testing for all your air tightness and  sound insulation testing.

How can I tell if an organisation is UKAS certified?

So, how can you tell if an organisation is UKAS certified? Well, all accredited businesses are allowed to use the Royal Crown symbol. Thus, you simply need to look out for this. Alternatively, you can head to the UKAS website at www.ukas.com , and you will find a list of all certified bodies under the ‘Accredited Bodies’ tab on the homepage. For peace of mind here is a direct link to APT sound testing’s UKAS accreditation.

We are a UKAS accredited company

Here at APT Sound Testing, we are happy to prove our UKAS certification. As a UKAS accredited laboratory we are committed to providing quality consultancy services to your business. If you want to know more about how we can help you with our UKAS accredited air and acoustic testing services, please contact us on 01525 303905 or email us at info@aptsoundtesting.co.uk  and we’ll be happy to talk you through our precompletion testing services or supply a free no obligation quote.

Searching for Sound Testing in London
Unless plans were fully approved prior to 1 July 2003, sound testing will be required on your London development between rooms or spaces that share a common area of separating wall and/or floor as stipulated in Building Regulations Part E for the passage of sound. Sound Testing is not generally required for internal walls and floors within a dwelling-house, flat or room for residential purposes; however, all internal partitions should be designed to achieve 40dB.

The buildings that require sound testing are:

1.            Dwelling-houses, flats or rooms for residential purposes created by conversion of existing buildings or new build rooms for residential purposes will need to be tested if work starts after 1 July 2004.

2.            New build dwelling-houses and flats will need to be tested if work starts after 1 July 2004.

The main aim of sound insulation testing in London is to ensure that minimum standards of sound resistance have not been compromised by poor workmanship and/or poor design. You are normally required to undertake sound testing to each type of construction, i.e. if you have a mixture of brick, blockwork, timber and metal studwork walls all four types would need to be tested, followed by a 10% sample of that type using the equipment shown in Plate A below.

For instance, if you have a project with 25 flats you would be required to do 3 x 6 pack of tests; each 6 pack contains 2 airborne wall, 2 airborne floor and 2 impact sound tests; however if any test failures occur, then the number of sound tests may need to increase on the development. When sound test failures occur, then the design and construction of the failed partitions will need to be revisited to try and evaluate the reasons for the failure; thereafter, agreement can be reached on how to rectify problem.

We have carried our hundreds of acoustic design reviews, so we are well placed to help you overcome any potential problems to achieve compliance with Building Regulations Part E.

When designing acoustic partitions you will need to consider the following:

a.            The careful design of floor plans to avoid habitual rooms being placed side by side.

b.            The mass and density of products that you are using.

c.             Using good design detailing to ensure the careful isolation of materials.

d.            The whole construction detail and how it is made up.

e.            Undertaking careful acoustic detailing of junctions between walls, ceilings and floors.

f.             Using acoustic wall ties in cavity walls.

g.            Types of doors in sound resisting walls.

h.            Containment of noise within noisy parts of a building such as lift shafts.

i.              Positions of sockets and flues on opposite sides of walls to ensure they don’t sit back to back.

j.             Sealing and filling of joints.

k.            The use of cavity closers on window/door reveals.

l.              Careful sealing of service penetrations.

m.           Designing to reduce potential reverberation in common parts of buildings such as corridors and entrance areas and the subsequent use of absorbent materials.

Unfortunately unless the acoustic design has been taken into account, the floor and ceiling partitions can be the main pathways for sound transmission.  The first type of sound transmission is airborne sound such as TV and speech; and the second is the passage of impact sounds such as footfall or children’s toys being dropped on the floor above.  Achieving good airborne and impact sound isolation requires careful acoustic design considerations.

Plate A below shows one cost effective ceiling upgrade that can be undertaken on conversion projects. Firstly retain the existing floor joists, then above the joists install 22mm chipboard. Above the floor board install an acoustic resilient membrane and above this install the 22mm engineered floor. Within the joist cavity install 100mm AW IsoWool. To the underside of the joists fix a resilient hanger system and below this install two layers of 12.5mm sound boards ensuring that boards have adequate laps. 

A simple Acoustic Floor Upgrade

To try and help our clients achieve compliance with Approved Document E, we offer the following 4 step acoustic design package:

1.            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.

2.            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.

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

4.            Pre-completion Sound Testing to satisfy Approved Document E.

APT Sound Testing can advise on all types of acoustic design, whether it’s accomplished during initial construction or during a refurbishment/renovation project.

We also undertake UKAS accredited sound testing providing a ‘one-stop’ solution for all your acoustic requirements.  If you would like more information in regards to sound testing please follow our blog at: http://soundtestinguk.blogspot.co.uk or visit the APT Sound Testing website..

Why Have I Failed my Sound Insulation Test?
This is one of the most common questions we get asked by clients when their property has failed the sound testing. One of the main reasons for acoustic partitions failing the Part E sound test is often down to poor isolation of material/s, which can lead to excessive noise flanking. Noise Flanking is a term used by acoustic engineers to describe where sound passes through an acoustic partition due to the abutment of materials. The noise simply hits one side of the wall and then travels through the construction via a noise bridge. This can be areas such as the incorrect use of masonry wall ties i.e. solid fishtail ties, used in place of specified acoustic wall ties.

Unwanted noise travelling along flanking paths can make the building structure vibrate, which can cause sound to radiate into your room. One simple cost effective solution is to build another wall or ceiling in front of the original, to offer extra isolation. For this upgrade to work you need to make sure that the independent wall or ceiling is not directly connected to the existing failed partition; so it provides isolation between materials.

Another reason for excessive noise flanking is often down to the use of down to the use of lightweight blocks in the construction of the building envelope. Due to the lightweight mas of the inner wall it allows sound to transmit from dwelling to another, both vertically and horizontally. If a building has failed its sound testing, it is essential to establish if the problem is due to direct transmission, flanking transmission or a combination of both so that the most cost and time effective remedial treatment can be designed and applied to the failed partitions. 

One of the easiest ways to reduce the chance of sound testing failures due to excessive noise flanking transmission is through careful consideration of the acoustic design at the start of the project.  Unfortunately, by simply specifying high-performance wall and floor partitions, it is no guarantee to adequate sound isolation and successful sound testing.

We offer preconstruction design advice to help you achieve successful sound testing in-line with Building Regulations Part E. We also offer onsite inspection services to ensure that the sound insulation elements are being installed as per manufactures guild-lines, as it’s no use having good acoustic design if it not being installed properly on site.

During early design and construction process, we visit site to conduct a comprehensive acoustic design survey and review, we also take this opportunity to meet; where possible, the site/project manager, architects etc. The first stage of the acoustic design is to send through the design drawings – to include sections etc. We then review the design to check that the construction details proposed are capable of passing the sound tests. This usually takes place straight after planning has been approved as increased cost savings can be realised at the earliest stage, we will evaluate the construction methods and materials specified to ensure that they are capable of meeting the acoustic requirements of Approved document E.

The typical areas we check are:

a.            There are no flanking points, where isolated partitions are wrongly mechanically fixed together to caused noise bridging.

b.            The walls and floors design are acoustically robust, to comply with Building Regulations Part E.

c.             The acoustic treatments for Soil Pipes, Stair Cases Steel Beams etc. to ensure they are acoustically fit for purpose, as these are some of the areas that get usually missed.

d.            Acoustic floor treatments are compatible with the proposed floor finishes i.e. Carpets, Laminates, Floor Tiles and under floor heating systems.

We also provide on-going design support service, so you will have direct contact with the allocated acoustician from the start of the process through to the successful completion of the project. One of the most important services is the going site survey visits which allow our clients to feel confident about the outcome 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.

We also offer an acoustic advice service for clients that have failed their sound testing. We offer simple solutions to reduce the noise levels and achieve compliance with Part E. We can supply simple easy to follow acoustic design reviews, utilising our extensive knowledge of different materials and construction methods

If you require more information about acoustic design and/or sound testing on your project, please visit the APT Sound Testing website or call direct on 07775 623464.

Sound Insulation Testing – Common Questions & Answers
To try and help our clients better understand Sound Insulation Testing for Approved Documents E, we have collated the most common and questions (along with answers) clients have asked us over the last ten years. If you have further questions not contained within this article then please don’t hesitate to contact us.

What is Sound Insulation Testing?
Sound insulation is the property of a wall and /or dividing partition to resist the passage of noise. The sound Insulation testing is a method of quantifying the sound insulation performance of walls and/or floors. Sound Insulation testing can be carried out on party walls, party floors or facades of any building.

Do I need sound insulation testing on my Property?
One of the largest single reasons for disputes between neighbours is noise complaints. Approved Document Part E – Resistance to the passage of sound describes minimum standards to be achieved by newly built domestic dwellings.

What is Approved Document E?

Approved Document Part E of the Building Regulations, sets out minimum standards for sound insulation performance to be achieved by party wall and party floors, you can achieve compliance with Part E by undertaking Pre-Completion Sound Testing

When is the Sound Testing carried out?
The Sound Insulation Testing is carried out when the buildings are complete. Windows should be in place with any vents closable. Internal and external doors should be in place, along with skirting, cornicing and plug sockets in place. Sound testing must be carried out before any soft coverings such as carpet have been laid to the floors. No furniture – such as beds or settees should be in the rooms during the sound testing as it will have an effect on the results. 

Are internal partitions within a single dwelling sound tested?
No, Laboratory test based performance standards (Rw) exist for certain internal walls and floors, but they are not intended to be verified as-built by on site measurement and therefore sound insulation testing is not a requirement; however, approved document E does state that internal partitions should achieve 40dB.

Do detached properties require sound testing for Part E of Building Regulations?
No, only attached properties require sound tests such as semi-detached dwellings or blocks of flats. Detached properties share no common partitions with any other properties.

How many sound insulation tests should I need on my Project?

Approved Document E states that one set of sound tests is required for every 10 units in a group or sub-group. A group or sub-group is defined where significant differences in construction or layout occur, for instance:

• For a pair of semi-detached Houses – a set of tests would usually comprise two airborne sound insulation tests of a separating wall.

• For Flats (up to 10 units) – a six pack would normally be required, this comprises of: two airborne wall tests, two airborne floor tests and two impact floor sound tests.

• For Rooms for Residential Purposes (student accommodation, hotel rooms, care homes etc.) – a set of tests would usually comprise: one airborne sound insulation tests of a separating wall; one airborne sound insulation test of a separating floor; one impact sound transmission test of a separating floor.
  

Which plots selected for sound testing?
We usually specify the amount of sound insulation tests that is required on each project and this will be shown on a schedule within our fee proposal. This allows our clients to forward the schedule to building control to seek their approval prior to the test. We first look at the floor plans then work out a testing schedule taking into account testing through the projects ‘habitable rooms’ i.e. lounges & bedrooms where possible. When we have specified the sound testing schedule it should always be checked by building control and/or the client to seek their approval before the commencement of sound insulation testing.

How do I Prepare my Site for Sound Insulation Testing? 

APT Sound Testing always send out a sound testing checklist along with our fee proposals to help you prepare for the sound testing, as we always want our clients to be fully prepared so they can pass their sound testing at the first attempt.

How long will the sound testing take?

The time taken to undertake the sound insulation testing varies with site conditions, but generally a ‘6 pack’ set of tests on houses and flats takes about one to two hours. Obviously this depends on the site being fully prepared in line with our sound testing checklist.

Will the sound insulation testing disrupt work on site? 
we require relatively quiet conditions are needed to take accurate measurements. This means that anyone working in the testing area will have to leave temporarily and any noisy works in the vicinity of the test rooms will need to be halted i.e. using power tools or loud hammering etc.  

How do I know if I’m ready for a sound insulation test?
We send out a checklist with all quotations to allow our clients to check they are ready for the sound testing. Basically the plots should be at least at second fix stage – for further details please refer to our sound test checklist.

What sound testing equipment do you use?

We use the latest UKAS calibrated acoustic equipment, for ease of use and reliability. unlike many other companies we able inform clients if they have passed or failed straightaway whilst on site. This allows us to offer acoustic advice and collect detailed construction information whilst on site, in the event of wall and/or floors failing the sound testing.

What if I only have 110V and not 240V on site?

Unfortunately we cannot undertake the testing off 110V or localised generator power; we will need 240V to undertake the sound testing.                   

Should I inform my neighbours of the impending sound testing?
If the building is attached in any way to occupied properties then you will need to inform the neighbours. We need to gain access to the neighbouring properties to undertake the sound test as we test the wall partition. You will also need to ensure that access is provided to the neighbouring properties throughout the sound testing.

Can you offer acoustic advice to help me to pass my sound testing?
APT offer an acoustic design service to help you design your buildings partitions to pass Part E sound testing. If you send through the relevant drawings such as sections and floor plans during the design stages of the project, we can check the design to see if there are any junctions or details where ‘noise flanking’ may occur, we can then advise if any changes are required to lower the chance of sound test failures.

Rest Assured

We believe in working with our clients on all types of projects from small end of terrace developments up to large blocks of flats. We believe that by being involved at the beginning of a project we can often save our clients expensive and difficult remedial works at the completion stage of a project.

If you need sound insulation testing for your current project, please call our team on 01525 303905 or email info@aptsoundtesting.co.uk  We can provide you with expert advice and are happy to offer a free, no obligation quote along with our informative

checklist to help you prepare for the sound testing.

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.

Improving Sound Insulation on Conversion Projects
Many of the dwellings in London and other UK Cities consist of flats which have been converted from large Victorian or Georgian houses, or more recently office blocks. Unfortunately designing for sound insulation is not always shown the highest priority so many converted 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.

We have helped many of our clients achieve compliance with Part E, by undertaking some simple steps. We can undertake an initial sample sound test of the existing wall and floor construction to ascertain the existing sound insulation levels. Once we have established the sound levels for the existing construction, we can then look at extent of the acoustic upgrades to attain Part E Compliance. This is much more effective than just forwarding an acoustic design that may be to excessive and expensive, especially if the existing floor and/or wall only needs to improve by a minimal amount such as 1-3dB. By having the existing sound levels of the partitions we can recommend targeted, acoustic upgrades to comply with Building Regulations Part E. 

The sound insulation levels required to pass Part E for refurbishment projects are less stringent than new build projects. Instead of 45dB for airborne its 43dB (2 dB less), and for instead of 62dB for Impact Sound Testing its 64dB on new build (2 dB more).

In our experience, refurbishment projects usually achieve 30-35dB for airborne sound and 70dB for Impact Sound during the sample sound test – if the existing construction has not been acoustically upgraded. These figures do not meet the required 43dB & 64dB as stipulated in Part E of Building Regulations. As sound double every 10dB this is a massive failure and major acoustic improvements must be made. Many existing construction consist of a similar construction as shown in as detail 1 below.

Detail 1: Existing Floor Partitions Rated At Approx. 30dB

Improving Wall and Floor Partitions

There are ways you can 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. However; by isolating the different materials may not be enough its own and you may need to improve the mass of the partition as well.

Existing Floor Partitions

In our experience, refurbishment projects usually achieve 30-35dB for airborne sound and 70dB for Impact Sound, if the existing construction has not been acoustically upgraded. These figures do not meet the required 43dB & 64dB as stipulated in Part E of Building Regulations. As sound double every 10dB this is a massive failure and acoustic improvements must be made. Many existing construction consist of a similar construction as shown in as detail 1 below.

Improving Existing 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. 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 – as per Detail 2 below:

Detail 2: Acoustic Flooring Partition Upgrade

Existing Wall Partitions

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 usually have the acoustic properties to pass Part E in their existing state due to lack of mass and poor isolation values. 

Improving 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 – it’s usually best to install this in the largest room backing onto the dividing partition. 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.

Detail 3: Met-sec Wall Upgrade

Taking the above into account is it essential that good acoustic design is addressed right from the start of the refurbishment project, so it prevents delays in handover, i.e. to prevent the dwelling failing the sound testing at building control signoff stage.– a common problem.

If you would like advice on your acoustic design or require sound insulation testing in London, please contact us now on 07775623464 or contact us at info@aptsoundtesting.co.uk.

Acoustic Design & Sound Testing Party Walls & Floors

The main design considerations for party walls and floors in dwellings.

To improve the chance of a successful sound test and reduce the chance of noise flanking you will need to ensure that you allow for the following five acoustic design considerations, when upgrading an existing floors and walls in flats they are:

1. Mass
2. Isolation
3. Absorption
4. Resilience
5. Stiffness

Reasons for party walls failing sound testing in Flats

The are many reasons for party walls failing the pre-completion sound testing for Part of Building Regulations, the main reasons are

1. Shared Structural Building Components – Floorboards, Floor Joists, Continuous Drywall Partitions, Continuous Concrete Floors, and Cement Block Walls.
2. Through Structural Steel – Structural steel beams are often a major cause of noise transmission as plasterboard is often fixed directly to the steel without sound breaks.
3. Plumbing Chases – Junctures between the Walls & Floor Slab Above or at the Exterior Wall Juncture (this should be filed with mortar etc. to add mass to these weakened areas.
4. Through Windows – if they have single glazing, with no double glazing or secondary glazing as a minimum.
5. Fixtures & Outlets – Light Switches, Telephone Outlets, and Recessed Lighting Fixtures (if penetrations have been cut back to back with the opposite dwelling under test)
6. Structural Joints – Perimeter Joints at Wall & Floor, Through Wall & Ceiling Junctures (these should be filled with acoustic mastic.
7. Around the End of the Partition Through the Adjacent Wall (acoustic mastic should be used to seal this junction)

Acoustic wall upgrade for Existing Flats

One way to quick and simple way improve the acoustic performance of a dividing wall partition, is to install a 70mm met-sec partition in front of the existing wall – it is usually best to install this in the largest room. Leave approx. 25mm gap between the back of the met-sec and the wall. Then install 50mm acoustic wool (min 45kg/m3) to the inside of the met-sec and add two layers of 12.5mm soundboard to the outside of the met-sec frame. Ensure all boards are fully lapped and the perimeter joints are filled with acoustic mastic.

What Sound Tests do I Need on My Party Walls.

Essentially, for sound testing party walls, you only need to carry out one type of sound test,  which is airborne sound testing. For floor partitions you are required to carry out two types of sound insulation tests which are airborne and impact sound insulation tests. The airborne sound insulation test is carried out by means of a loudspeaker emitting a steady source of noise on one side of the partition (wall or floor) to be measured

How Should I Prepare my Dwelling to Pass the Party Wall Sound Testing?

It is easy to prepare your new project for the sound insulation testing to your party walls, basically you should action the for the following checklist:

1. The whole building envelope and internal walls and floors should be fully completed prior to the undertaking sound testing.  
2. All external and internal doors and walls should be installed.
3. All electrical fittings must be completely in-place, and fully functional. Poor electrical installation can lead to excess noise.
4. 240 volt power should be in-place and available in every room. Our testing equipment can be damaged  by the voltage fluctuations of on-site power generators, so it’s essential to have 240V mains supply on-site on the day of the test
5. No carpets or laminated flooring should be fitted on the 1st floor levels or above. These materials can affect the movement of noise, and as a result could impact on whether a building passes the sound check test.
6. The skirting boards should not touch the floating floor, a flanking strip should be installed to prevent the noise flanking.
7. All gaps in the walls and floors should be sealed. Again, noise can leak out through any gaps, affecting the movement of sound and impacting on the space’s performance.
8. Access to all of the rooms on all levels should be granted to our technicians, with all noise sources (radios, alarms, building work) ceasing for the duration of the test.
9. The above points are all essential if we are to achieve accurate sound test readings.  If any of them are ignored, there is a risk of you either failing your test or – at worst – not being able to complete it, at which point you may still be charged 75% of the test fee.

We can advise on all types of acoustic design to help you pass your sound testing to walls in flats, whether it’s accomplished during initial construction or during a refurbishment/renovation project. We also undertake UKAS accredited sound testing providing a ‘one stop’ solution for all your acoustic requirements.

If you would like more information in regards to sound testing please follow our blog at: http://soundtestinguk.blogspot.co.uk or contact us at: info@aptsoundtesting.co.uk or call Darren Direct on 07775623464. Alternately, if you would like more information on how to prepare for your sound testing please download our sound test checklist.