What Types of Sound Testing are required for Approved Document E?

Sound insulation testing must be carried out on new build and conversion dwellings. The dwellings will either require Airborne and/or impact sound testing depending on the type of dwelling. For houses airborne wall tests are usually required; however, for flats you usually need to carry out airborne wall, airborne floor and impact sound testing.

Here is a brief explanation on the two types of sound insulation tests:

Airborne Sound Tests – Airborne tests are carried out on party walls and floors/ceilings between dwellings. Airborne sound testing measures levels of sound transmitted through the air. We use a Norsonic loudspeaker that produces white noise on one side of the partition, and measure with a decibel meter on the other side how much sound is lost through the partition.

Examples of airborne noise that you usually expect to find in dwellings are people talking, radios and televisions.

Impact Sound Tests – These are only carried out on separating floor/ceiling divides between dwellings – usually on flats. An impact test measures the levels of noise transmitted directly through a separating construction as a result of impact noise, which emulates footfall noise from above. To produce footfall noise we use a tapping machine, which drops metal hammers onto the floor to create impact noise. We then measure the amount of sound that passes through the partition with a decibel meter in the room below the floor partition.

All testing should be carried our between ‘habitable’ rooms. Habitable rooms can be lounges, bedrooms, studies, living rooms and kitchens. Test findings are fed into an Approved Document E complaint report that will be then sent to the client to pass on to the tasked building control body. This sound test report should always be acceptable to Building Control and will help you to get your development signed off.

We provide a turnkey acoustic solution for consultants, project managers and developers from the design stage of developments, right through to the final precompletion testing, ensuring our clients have peace of mind when it comes to the acoustics on their projects.

APT Sound Testing is UKAS accredited to undertake Sound Insulation Testing under ISO/IEC 17025:2017. As a UKAS accredited laboratory we are required to attain the highest standards at all times.

For further information, please see our frequently asked questions section, or to prepare for your sound testing please download our sound test checklist.

For more information please contact us at info@aptsoundtesting.co.uk or call us on 07775623464. Alternately, for more information please visit our website at www.aptsoundtesting.co.uk

Sound Insulation Testing Information for Clients

Sound insulation testing or pre-completion sound testing must be carried out on new build dwellings as well as on converted dwellings. The dwellings will either require an Airborne sound test or an Airborne and Impact sound test. Airborne tests are carried out on separating walls between habitable rooms of dwellings such as houses or flats. Airborne and Impact sound tests are carried out on the separating partition floors between habitable rooms of flats. All sound insulation testing must comply with Approved Document E of Building Regulations.

All of our sound insulation tests are carried out in accordance with ISO 140-4 and ISO 140-7 and we are a UKAS accredited test laboratory, so you can be safe in the knowledge that all our sound testing is carried out to the highest standards in compliance with ISO 17025/2017.

New build properties need to meet the requirements of DnTw+Ctr ≥45dB (more than) and LnTw  ≤62dB (less than).  Conversion properties need to meet the requirements of DnTw+Ctr ≥43dB (more than) and LnTw ≤64dB (less than).

APT Sound Testing test engineers have over 15 years of experience in sound insulation testing throughout London and the South East. We are experts in acoustic consultancy as well as the testing, having completed hundreds of acoustic design projects jobs throughout the UK. We take pride in offering all of our clients a personal and comprehensive acoustic service which is reflected in our positive google reviews and testimonials.  (See our positive customer testimonials here)

We provide a turnkey acoustic solution for consultants, project managers and developers from the design stage of developments, right through to the final precompletion testing, ensuring our clients have peace of mind when it comes to the acoustics on their projects.

What Is Sound Insulation Testing for Approved Document E?

As we have explained, Sound insulation testing must be carried out on new build dwellings as well as on converted dwellings. The dwellings will either require an Airborne sound test or an Impact sound test depending on the dwelling type.

Here is a brief explanation on the two types of sound tests:

Airborne Sound Tests – Airborne tests are carried out on party walls and floors/ceilings between dwellings. Airborne sound testing measures levels of sound transmitted through the air. We use a Norsonic loudspeaker that produces white noise on one side of the partition, and measure with a decibel meter on the other side how much sound is lost through the partition.

Examples of airborne noise that you usually expect to find in dwellings are people talking, radios and televisions.

Impact Sound Tests – These are only carried out on separating floor/ceiling divides between dwellings – usually on flats. An impact test measures the levels of noise transmitted directly through a separating construction as a result of impact noise, which emulates footfall noise from above. To produce footfall noise we use a tapping machine, which drops metal hammers onto the floor to create impact noise. We then measure the amount of sound that passes through the partition with a decibel meter in the room below the floor partition.

All testing should be carried our between ‘habitable’ rooms. Habitable rooms can be lounges, bedrooms, studies, living rooms and kitchens. Test findings are fed into an Approved Document E complaint report that will be then sent to the client to pass on to the tasked building control body. This sound test report should always be acceptable to Building Control and will help you to get your development signed off.

For further information, please see our frequently asked questions section, or to prepare for your sound testing please download our sound test checklist.

APT Sound Testing is UKAS accredited to undertake Sound Insulation Testing under ISO/IEC 17025:2017. As a UKAS accredited laboratory we are required to attain the highest standards at all times.

It is common knowledge that the assessment criteria used by UKAS are internationally recognised as being the best indicators of accurate, impartial and consistent performance. UKAS accreditation demonstrates an organisation’s competence, impartiality and performance capability against internationally recognised standards.

For more information on our Acoustic Design services and Sound Testing services in London, please give me a call direct on 07775 623464  or email us at info@aptsoundtesting.co.uk

Want to Know More About Sound Testing?

Airborne and Impact Sound is transmitted through most walls and floors by setting the entire structure into vibration. This vibration generates new sound waves of reduced intensity on the other side. The passage of sound into one room of a building from a source located in another room or outside the building is termed ”sound transmission”. 

Sound transmission loss or Sound Reduction Index, R dB, is a measure of the effectiveness of a wall, floor, door or other barrier in restricting the passage of sound. The sound transmission loss varies with frequency and the loss is usually greater at higher frequencies. The unit of measure of sound transmission loss is the decibel (dB). The higher the transmission loss of a wall, the better it functions as a barrier to the passage of unwanted noise across the dividing (acoustic) partitions.

Sound Testing Explained

Approved Document E stipulates that there are two types of sound insulation in buildings: airborne and impact. Airborne sound insulation is used when sound produced directly into the air is insulated and it is determined by using the sound reduction index. Impact sound insulation is used for floating floors and it is determined by the sound pressure level in the adjacent room below.

A sound insulation test of a separating partition will be considered as a pass if the airborne sound insulation is equal to or greater than the DnT,w + Ctr value shown for the appropriate dwelling in the table, for airborne testing in new builds properties a figure of 45dB or greater is required and for Impact testing 62dB and below. For conversion properties a figure of 43dB or greater is required and for Impact testing 64dB and below.

What is DnT,w

DnT,w is an in-situ measured performance parameter which demonstrates the level of resistance to sound transmission between two adjacent spaces, such as flats or houses. The measurement will include both direct sound transmission and flanking sound transmission of the construction. Flanking transmission is the effect of sound travelling through the building and may be particularly evident where beams and joists bridge a common partition or along poorly isolated lightweight wall constructions.

The DnT,w of a separating wall or floor will typically be of the order 5 to 7 dB lower than the manufacturers specified Rw (single figure quantity of sound insulation) for the single element, due principally to the contribution from flanking sound transmission around the element when it is built on site – this should always be accounted for in the initial acoustic design.

What is Ctr

Ctr is the spectrum adaption term. It is a correction attributed to the sound insulation quantity to account for urban traffic noise.

What is L’nT,w

L’nT,w is an in-situ measured performance parameter which demonstrates the level of resistance to impact sound transmission between floors. The impact measurement includes both direct sound transmission and flanking sound transmission.

Weighted Sound Reduction Index Rw

When specifying the acoustic performance of an acoustic partition in a more general manner, it can be useful to describe the sound insulation by a single number. The weighted sound reduction index, Rw , is a rating method given in EN ISO 717-1. This standard fits a standard reference curve to the measured sound reduction index curve.

Within the EN ISO 717-1 standard, a rating method is also given where the Rw value is completed by two C-terms which are applied to two models of the noise spectra for various types of noise. These two terms, Rw + C and Rw + Ctr, also include the frequency range 100 – 3150 Hz but can be extended to 50 – 5000 Hz. As industrial and traffic noise often have high sound levels which are also below 100 Hz, it is recommended that the extended frequency area is used.

The summary value, Rw + C, gives the reduction value in dBA for a spectrum with a level which is equally high in all third-octave bands. This can be used for:

•             Highway road traffic travelling at speeds in excess of 80 km/h

•             Factories emitting mainly medium and high frequency noise

•             Living activities (talking, music, radio, TV)

•             Railway traffic at medium and high speed

•             Jet aircraft at a short distance

The summary value Rw + Ctr also gives the reduction value in dBA, spectrum with low-frequency dominance such as:

•             Disco music

•             Urban road traffic

•             Railway traffic at low speeds

•             Factories emitting mainly low and medium frequency noise

Both the impact and airborne insulation performance of floors and walls should be carefully considered from the start of the project to ensure that the minimum performance requirements for new and converted developments are met inline with Approved Document E

If you would like more information in regards to our sound testing and/or noise survey services, please contact us now at info@aptsoundtesting.co.uk.

Identifying Building Defects: Thermographic Building Surveys

Thermography measures surface temperatures of buildings by using infrared cameras. These instruments see light that is in the heat spectrum. Images on the video record the temperature variations of the building’s envelope, ranging from white – for warm regions, to black for cooler areas.

The resulting thermal images help the thermography engineer to determine whether insulation is required within existing buildings and/or there is missing insulation in new build projects and it has been installed correctly. Thermal imaging can also identify excessive cold bridging, air leakage, breaks in insulation and/or electrical and mechanical faults.

Thermographic Building Inspections to Commercial Building Envelopes

A thermal building inspection can be carried out to both the exterior and interior of buildings. The energy assessor usually decides which method would give the best results under the prevailing weather conditions. For instance for BREEAM, external thermal imaging inspections are more common. However, if it is windy on the day of the test it may be harder to detect temperature differences on the outside surface of the building; because of this difficulty, interior surveys can be more accurate because they benefit from reduced air movement.

Thermographic building inspections can also be used with blower doors used for air tightness testing. The blower door helps exaggerate air leaking through defects within the building envelope i.e. the floors, walls and roof. Air leakage paths will appear as black streaks in the infrared camera’s viewfinder. Here is some more information on using the powerful combination of air tightness testing and thermal imaging for BREEAM building inspections.

We hope this information has been helpful. If you require a Thermal imaging survey on your building, our professional and certified Level 2 thermographer’s will carry out your thermographic Inspection in compliance with all necessary standards and current regulations. All we need are a few details such as floor plans and elevation drawings and the building location to provide a quotation. We will also send across our informative checklist to help you prepare for the thermal survey.

For more information please contact us at info@aptsoundtesting.co.uk or visit our website at www.aptsoundtesting.co.uk

The importance of thermal imaging on Commercial Buildings.
Thermal imaging inspections are the best way to assess continuity of insulation once the building fabric is complete on commercial buildings. It is also a very effective method of locating air leakage paths in a completed building.

This article discusses the legal requirements in Building Regulations and also the availability of BREEAM credits for thermal imaging, as well as England & Wales Building Regulations and supporting guidance, specifically Part L (Conservation of Fuel and Power).

At the time of writing this publication, it was not known what form these would take. Building Regulations for England and Wales require that reasonable provision shall be made for the conservation of fuel and power in buildings by trying to limit heat gains and losses through thermal elements and other parts of the building fabric. This requirement is supported by guidance in four Approved Documents:

• • • • Approved Document L1A – New Dwellings
      • Approved Document L1B – Work in Existing Dwellings
      • Approved Document L2A – New Non-Dwellings
      • Approved Document L2B – Work in Existing Non-Dwellings

The above approved documents highlight the importance of thermal imaging for investigating the thermal performance of the building envelope. The four Approved Documents also provide the following guidance: “The building fabric should be constructed so that there are no reasonably avoidable thermal bridges in the insulation layers caused by gaps within the various elements, at the joints between elements, and at the edges of elements such as those around window and door openings”.

All our APT’s thermographic engineers hold a minimum of Level 2 certification. We use the latest Flir high resolution thermal imaging cameras for all our surveys. Thermal imaging is the only practical way of checking that thermal insulation hidden in the structure meets the requirements for continuity of insulation.

More details for both our thermal imaging and air tightness testing services can be found on our website at www.aptsoundtesting.co.uk.

Please visit us at for our thermal imaging guide and checklist and here for our air tightness testing guide and checklist.

If you would like more information on our Themographic Building Inspection service, please contact us at info@aptsoundtesting.co.uk or call us on: 01525 303905

Thermal Imaging Inspections and Air Tightness Testing a Powerful Combination. The importance of thermographic inspections and air tightness testing cannot be understated when investigating the integrity of your commercial building envelope; it is also one of the only ways to accurately check that thermal insulation hidden in the structure meets the requirements for continuity of insulation.

in the case of new buildings, it is a requirement to carry out airtightness testing – once the designed air leakage rate has been established and once completed the measured air permeability is fed into the CO2 emissions calculations. In the case of existing buildings, the guidance on continuity of insulation only applies where new thermal elements (for example walls, floors, and roofs.) are provided, for example when an extension is built. There are no requirements for CO2 emissions calculations or air-tightness testing on existing buildings; although this may be a client requirement.

Regulation 43 of the Building Regulations for England and Wales requires air pressure testing to be carried out on all new buildings, in order to be satisfied that provision has been made to limit heat gains and losses through the building fabric. This includes heat transfer by air leakage. For new dwellings, Building Regulations Approved Document L1A [1] requires air tightness testing be carried out on a representative sample of dwellings – although this has since been changed to all dwellings. Approved Document L2A relating to new buildings other than dwellings requires an air leakage test to be carried out on all buildings subject to the regulations in accordance with the standard test method.

APT Sound Testing uses the latest Flir high resolution thermal imaging cameras for all our surveys and our thermographic engineers hold a minimum of Level 2 certification – the minimum required to undertake BREEAM thermal surveys.

More details for both our thermal imaging and air tightness testing services can be found on our website at www.aptsoundtesting.co.uk. Also, to help you prepare your building for thermal imaging and air tightness testing, please download our thermal imaging guide and checklist and here for our air tightness testing guide and checklist.

If you would like more information on our Thermographic Building Inspection service, please contact us at info@aptsoundtesting.co.uk or call us on: 01525 303905

Thermal Building Inspections in London
Thermographic surveys are an indispensable tool for demonstrating where heat is being lost in your commercial buildings in London.   Most of our customers are very surprised at mount of the sources of heat loss we uncover on their buildings. The problems can be cold draughts emanating through air leakage paths/cracks they hadn’t even noticed as well as missing insulation from whole sections of walls and/or floors which have been missed out by the insulation installation companies.

How Does a Thermal Building Inspection work?

We will book in a convenient time to visit your commercial building in London; naturally this will depend on the time of year, in November-April the surveys can be undertaken fairly late in the morning; however, between May to October the surveys usually need to be undertaken between the hours of 03.00 – 05.00 to prevent solar loading etc.  Sometimes due to the prevailing weather conditions such as heavy rain etc. we may need to cancel the test and rearrange for a more suitable weather conditions – we will always try to give our clients as much notice as possible if there is a the chance of cancellations.

When we have undertaken the thermographic inspection, we will discuss any problems we  have encountered so you have an overview of the survey prior to us leaving site – obviously this takes more time but we feel it an important part of our service.

                                                                                                         
How long does will a Thermal Imaging Survey take?

This depends on the size and accessibility of your building, but it also depends how involved our clients want to be.  We strongly encourage advise that a site representative is with us during the survey as the customers representative will know more about the building, and we can point out any issues which can then be answered on the spot. By having a ‘buddy’ working alongside us we will both learn more in the process, which will ultimately help us to help you.  Overall we suggest our clients allow a minimum of 1 – 2 hours for a survey – especially if you have a lot of questions and it’s a large commercial building.

What type of Thermal Imaging Inspection report will I receive?

Usually within 1-2 days you will receive your thermal imaging report in PDF format, including copies of the images recorded, and our interpretation of what they are indicating

You might be interested to know that our Thermography Engineers are trained to minimum of Level 2, so the quality of the reportage is always of the highest quality.

Our Thermal Imaging Equipment

We use the latest Flir high resolution thermal imaging camera – our model is specifically designed for building thermography, with increased sensitivity incorporating a photographic image with an overlay of the thermal image, a feature which helps to put the latter into the context of its surroundings and offers our clients extra clarity when they are trying to reference the different areas of the buildings. We have 20 years’ experience working in a consultant thermography role so we bring a huge amount of experience to all our surveys.

It is worth noting that if a thermographic survey is being undertaken as part of a BREEAM assessment, the thermography engineer must be qualified to a minimum Level 2 – all our APT’s thermographic engineers hold a minimum of Level 2 certification. We use the latest Flir high resolution thermal imaging cameras for all our surveys. Thermal imaging is the only practical way of checking that thermal insulation hidden in the structure meets the requirements for continuity of insulation.

Please visit us at for our thermal imaging guide and checklist and here for our air tightness testing guide and checklist.

If you would like more information on our Thermographic Building Inspection service, please contact us at info@aptsoundtesting.co.uk or call us on: 01525 303905

Alternately for more information on our full range of thermal imaging inspection services, please visit our website at www.aptsoundtesting.co.uk

The need for thermal imaging on Commercial Buildings

Thermal imaging is the best way to assess continuity of insulation once the building fabric is complete on commercial buildings. It is also a very effective method of locating air leakage paths in a completed building.

This article discusses the legal requirements in Building Regulations and also the availability of BREEAM credits for thermal imaging, as well as England & Wales Building Regulations and supporting guidance, specifically Part L (Conservation of Fuel and Power).

At the time of writing this publication, it was not known what form these would take. Building Regulations for England and Wales require that reasonable provision shall be made for the conservation of fuel and power in buildings by… limiting heat gains and losses… through thermal elements and other parts of the building fabric. This requirement is supported by guidance in four Approved Documents:

• Approved Document L1A – New Dwellings
• Approved Document L1B – Work in Existing Dwellings
• Approved Document L2A – New Non-Dwellings
• Approved Document L2B – Work in Existing Non-Dwellings

The above documents highlight the importance of thermal imaging for investigating the thermal performance of the building envelope. The four Approved Documents also provide the following guidance: “The building fabric should be constructed so that there are no reasonably avoidable thermal bridges in the insulation layers caused by gaps within the various elements, at the joints between elements, and at the edges of elements such as those around window and door openings”.

In the case of new dwelling and/or commercial buildings, linear transmittance values for the specific construction details used are fed into the CO2 emissions calculations required by Building Regulations Part L. Preference is given to accredited construction details by imposing a penalty in the CO2 emissions calculations for non-accredited details.

Also in the case of new buildings, it is a requirement to carry out airtightness testing – once the designed air leakage rate has been established and once completed the measured air permeability is fed into the CO2 emissions calculations. In the case of existing buildings, the guidance on continuity of insulation only applies where new thermal elements (for example walls, floors, and roofs.) are provided, for example when an extension is built. There are no requirements for CO2 emissions calculations or airtightness testing on existing buildings; although this may be a client requirement.

Regulation 43 of the Building Regulations for England and Wales requires air pressure testing to be carried out on all new buildings, in order to be satisfied that provision has been made to limit heat gains and losses through the building fabric. This includes heat transfer by air leakage. For new dwellings, Building Regulations Approved Document L1A [1] requires air pressure tests to be carried out on a representative sample of dwellings – although this has since been changed to all dwellings.

Approved Document L2A relating to new buildings other than dwellings requires an air leakage test to be carried out on all buildings subject to the regulations in accordance with the standard test method.

It is worth noting that if a thermographic survey is being undertaken as part of a BREEAM (Building Research Establishment Environmental Assessment Method) assessment, the thermographer must be qualified to a minimum Level 2 – all our APT’s thermographic engineers hold a minimum of Level 2 certification. We use the latest Flir high resolution thermal imaging cameras for all our surveys. Thermal imaging is the only practical way of checking that thermal insulation hidden in the structure meets the requirements for continuity of insulation.

More details for both our thermal imaging and air tightness testing services can be found on our website at www.aptsoundtesting.co.uk.

Please visit us at for our thermal imaging guide and checklist and here for our air tightness testing guide and checklist.

If you would like more information on our Themographic Building Inspection service, please contact us at info@aptsoundtesting.co.uk or call us on: 01525 303905

The Four Steps to Successful Sound Testing

New homes are built to high standards; however, acoustics and noise control are important factors requiring careful consideration during design and specification, as well as pre-completion commissioning testing. Why choose APT Sound Testing? We provide full turnkey solution to help our clients achieve Building Regulations Part E compliance. We provide a professional acoustic consultancy service to help developers tackle the key issues. We have carried out thousands of sound insulation tests since 2006 so we have a large amount of experience in regards to Building Regulations Part E compliance.

Our Four Stages Areas of expertise of tackling sound are:

Acoustic Design
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. so APT Sound Testing can 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.

APT Sound Testing 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:

• There are no flanking points, where isolated partitions are wrongly mechanically fixed together to caused noise bridging.
• The walls and floors design are acoustically robust, to comply with Building Regulations Part E.
• 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.
• Acoustic floor treatments are compatible with the proposed floor finishes i.e. Carpets, Laminates, Floor Tiles and underfloor heating systems.
  
  

Ongoing Site Construction
We provide the site team with 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 that still fails due to poor workmanship; the site survey visits negate the risk of sound test failure.

Pre-completion Sound Testing
Sound Testing for Part E of Building Regulations has been a mandatory requirement since July 2003. All new build dwellings and conversions which were built after this date require 10% of each party wall/floor construction type to be tested. Sound testing needs to be carried out between pairs of rooms separated by party walls and/or floors. In most cases the rooms to be sound tested will be the two main habitable rooms, i.e.  living rooms and bedrooms. The sound test procedure involves setting up a noise source in a room on one side of the party wall or floor and measuring the noise on both sides of the partition.

There are two types of sound insulation testing – airborne and impact. Airborne tests may be required between horizontally and vertically separated pairs of rooms. The sound tests are undertaken by using a sound source, amplifier and loudspeaker to generate a high noise level in one room (the source room). Noise measurements are then taken in both the source and receiver rooms using a prescribed number of source and microphone positions. The background levels in the receiver room are measured and the reverberation time in the receiver room is also measured.

For vertically separated rooms, an Impact sound test may also be required. Impact testing is undertaken using a “tapping machine”, (as above) which drops a series of weights onto the floor of the upper room. The noise level in the lower (receiver) room is measured for a prescribed number of source and microphone locations. The background levels in the receiver room are measured and the reverberation time in the receiver room is also measured.

All APT’s test engineers carry the latest Norsonic equipment, which are class one rating all of our acoustic testing/sound testing is completed to a strict quality controlled standard. We provide full ISO & UKAS complaint sound testing.

Post Occupancy Sound Testing and Advice
We have carried out sound insulation testing and investigative/diagnostic work can help identify problems, especially if the specific properties of concern were not tested as part of a programme of precompletion testing. We also carry out sound testing and offer acoustic design advice where clients may have not followed the rules of their buildings lease agreements and installed timber floor etc. instead of the usually specified carpet finishes.

If you would like more information in regards to our acoustic design and/or sound insulation testing, please contact us at: info@aptsoundtesting.co.uk  or visit our website at: www.aptsoundtesting.co.uk. Alternatively you can call our team on 07775623464. 

Sound Insulation Testing in London
London is a massive city containing over 9 million people density and high rise apartments. With many living in this overcrowded environment it is essential that noise transference between adjoining properties in kept to a minimum for the occupant’s wellbeing. One way of ascertaining that a building is in compliance with Building Regulations Part E for the prevention of noise transference, is to undertake Sound Insulation Testing in London.

We have undertaken thousands of sound insulation tests throughout London and the South East on all types of projects from simple flat conversions to large developments containing hundreds of flats. We also undertake Sound Insulation Testing where a lease holder dispute has arisen, i.e. where the buildings lease stipulates that wooden floors should not be used instead of carpets and as a result of the change of floor finish the noise levels have increased – especially the impact noise. We can also undertake sample sound testing to highlight the existing noise levels so a targeted acoustic design can be undertaken.

Plate A – Tapping Machine for Impact Sound Testing

Currently we are also experiencing a rise in the amount of sound testing required to existing blocks of flats, such as existing council stock. This is hardly surprising as the amounts of noise complaints have more than doubled within the last 10 years due to residents experiencing excess noise between the dividing wall and floor partitions.  By utilising our extensive knowledge of different materials and construction we can forward a simple, explanative cost effective solution for wall and/or floor upgrade. Where our clients have followed our advice they have achieved a 100% success sound test pass rate, ensuring compliance with Part E of Building Regulations.

The Sound Testing procedure is fairly simple and our engineer will be happy to explain this on site. Essentially, for party walls there is one type of sound insulation test which is airborne sound test and for compartment floors there are 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. The corresponding sound level is measured on the other side of the partition. Impact sound insulation tests are carried out by means of a tapping machine placed on the floor sample to be measured and the noise measured in the room or space below

All our engineers carry out the sound test measurements in full accordance with the measurement procedures of BS EN ISO 140-4:1998[3] for field measurements with a single figure DnTw and LnTw in accordance with BS EN ISO 717.

Ongoing problems with airborne and structure borne sound are often associated with direct noise flanking transmission through floors and supporting walls and other associated structures. One common cause of noise flanking is often associated with the inclusion of lightweight blocks within the construction of the building envelope and/or blocked cavities. It all cases it is essential to establish if your problem is due to direct transmission, flanking transmission or a combination of both so that the most cost effective remedial treatment can be chosen.

Unwanted noise travelling along flanking paths will make the building structure vibrate which causes the sound to radiate into your room. One simple cost effective solution is to build another wall or ceiling in front of the original, but not connected to it (often called an independent wall or ceiling) so it provides isolation between materials.

One way to reduce the chance of flanking transmission is through careful consideration to the 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.

APT Sound Insulation Testing
We offer both preconstruction and post-construction design solutions if a project has failed the sound testing. We also offer onsite inspection services to ensure that the sound insulation elements are being installed as per manufactures guild-lines.

If you require pre-completion sound testing and/or you would like acoustic design advice on your project, please contact us now at info@aptsoundtesting.co.uk.