How Much Does a Thermal Imaging Inspection Cost?

We often get asked ‘what’s the cost of a thermal survey’. It depends on numerous factors, such as the size and amount buildings you need to be surveyed, the project location, and the detail required for the thermal survey report.

The Thermal Imaging Inspection

This is a very common question clients ask us and it has a simple answer: it depends on numerous factors.  When we sit down to work out our fee proposal for a Thermal imaging inspection, we ask the client a number of questions:

1. The type and size of building.
2. The amount of preparation required?
3. The amount of time required to safely undertake the survey.
4. The type of equipment required to undertake the inspection.
5. The project location and subsequent travel costs/time.
6. The required deliverables – what needs to be included within the thermal survey report.
7. The amount of health and safety requirements i.e., some sites ask for 4-hour safety induction

So, taking the above into account we can offer a basic electrical thermal survey to a couple of distribution boards for £495 plus Vat, right up to the huge industrial areas, that may require multiple visits that may be in excess of £10,000 plus Vat, and of course everything in between. In all instances it’s best to call us so we gain a more accurate overview of our project and quoted; accordingly, so please contact us to discuss your project (along with any site-specific issues) and obtain a quote.

Is your thermal imaging company adequately trained?

When you are employing a thermographer, you should check to see that they incorporate the high specifications possible for their inspections. Are they certified to Level 3 and do they use large format FLIR thermal imaging cameras, anything less and you may not get the thermal imaging report you need to comply with BREEAM. 

Their specification should include:

1. Level 3 thermographic certification
2. Level 3 qualified thermographers
3. Large format FLIR cameras with 45-degree lenses

The importance of clear and concise thermographic reports

We spend such a large amount of time on our thermal imaging reportage, that’s why it’s one of the best in the industry, this is obviously a part of the service which is off-site and clients don’t see. Whilst we may draw initial conclusions on-site, which may need more investigation; usually, our final conclusions and report will only be finalised after all the data has been studied. It’s our ongoing aim to provide thermographic reports that are clear, concise, and easy to reference. Our aim is to take the guesswork out of the equation.

Please contact us for more information on Thermal Inspection Services

Our team of Level 2 & 3 certified professional Thermographers is highly experienced in carrying out thermal imaging surveys and have many years of experience in all aspects of engineering, construction, maintenance, management, and professional survey work.

Our thermal imaging equipment is the best and most accurate on the market, ensuring we pick up faults that other equipment may miss. Our reports are professionally presented and are clear, concise, and easy to follow. We endeavour to give our clients a first-class service every time.

If you would like to contact us for more information on our thermal imaging services, please contact us on 01525 303905 or email us at info@aptsoundtesting.co.uk. Alternatively, if you would like more information on how to prepare for your thermal imaging survey, please visit our website or download our thermal imaging checklist.

Improving Separating Walls and Floors to Pass Part E Sound Testing

Approved document E of Building Regulations stipulates a minimum soundproofing standard for all new flats and houses with shared walls as well as conversion projects where house have been converted into flats. Usually, in newly built homes, you shouldn’t suffer noise issues with neighbour noise, unless they are creating very loud noise that is an environmental nuisance i.e., playing their music at 90dB.

Suffering excess noise through separating walls or floors can be a big problem for residents, and more so at night after 10pm, when there is less background noise to help the situation as noise becomes more noticeable. 

Excess noise is a very common in older houses and flats constructed prior to 2004, as the dwellings may have been created with separating walls and floors, with no consideration to the sound insulation. In many of these older conversion properties, excess noise can be a huge issue as it usually consists of a timber joist with existing floorboard above and one single later of 12.5mm plasterboard below. This type of construction usually achieves around 30dB (Approved Document E, requires a minimum of 43dB for conversion properties) so normal residential noise such as speech can be easily heard from adjoining neighbours.  

One simple way to upgrade the floor would be to add insulation between the joists, with acoustic resilient membrane above the flooring. Below the joists resilient bars can be installed along with two layers if 15mm soundboard. You can easily achieve 46-48dB by using the above acoustic treatment, as long as its installed inline with manufacturers details. 

What’s the difference between airborne and impact noise?

There are two types of noise that usually become an issue between neighbours, airborne and impact noise; however, on closer inspection they are quite different! Airborne noise is created by speech, TV and music; whereas, impact noise is created by footfall, doors banging such as kitchen cupboard doors. In many instances impact noise is more annoying as its usually a loud thump similar to a banging of a drum sound. Impact sound can also radiate through the fabric of the building via walls etc.

Sometimes it’s a good idea to ask your neighbour to come around to your property so they can hear the noise disturbance, more often than not there can be a fairly simple solution such as replacing kitchen cupboard doors with soft closing hinge; or installing a large rug to the middle of the floor.  You may even be able to do a deal where you pay half the costs which should speed up the process.  

What’s Leaseholder Sound Testing?

We often get involved in leaseholder sound testing, for this type of test we undertake a sound test visit to check the sound insulation performance of the existing floor partition prior to the commencement of construction works. Thereafter, once the construction works are completed, we visit site a second time to check the acoustic performance of the newly upgraded floor is not worse than the original construction.

We can help with the acoustics on your project

Hopefully, this article will offer some guidance to help you soundproof your separating wall to reduce excess noise through the floors and help to improve the acoustic insulation values in-line with Approved Document E standards.

If you would like some more information, please give our team of friendly acoustic design consultants a call to discuss your project and let us take the stress out of soundproofing! We can undertake the initial acoustic design of your party walls and thereafter the sound testing to check the sound proofing of your party wall. For more information please email us at: info@aptsoundtesting.co.uk or visit our website here. Alternatively please call us on 07775 623464

What Types of Sound Insulation Testing is Needed on Flats?

There are two types of sound tests that are required for flats to comply with Approved Document E; they are:

Airborne Walls and Floor Tests – These types of sound tests are carried out on separating walls and floors/ceilings between flats. An airborne sound test measures levels of sound transmitted through the air, such as speech and TV and Music noise. We use the latest Dodecahedron loudspeakers that produces white noise on one side of the partition, and measure noise with a Level 1 decibel meter on the other side of the partitions to check how much sound is lost through the partition.

Impact Floor Tests – This type of sound tests is only carried out on separating floor/ceiling divides between dwellings. An impact test measures the levels of noise transmitted directly through a separating construction as a result of impact noise such as footfall.  We use a Norsonic 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 on the other side of the dividing partition.

All types of sound insulation testing should only be completed on ‘habitable’ rooms. Habitable rooms can be Lounges, Living Rooms, Studies, bedrooms and open plan kitchens. Test findings are fed into a report, that will compare the results against the Part E Building Classification, which will clearly show a pass or fail. Thereafter the sound test report, will be sent to the client. As a UKAS accredited testing laboratory, our sound test report should always be acceptable to your tasked Building Control, and will help you to achieve building signoff for Approved Document E.

We know how important a sound insulation certificate is to you in achieving building control signoff, that’s why we pull out all the stops to make certain that you get the certificate quickly. We pride ourselves on the fact that our sound insulation certificates are issued with speed and efficiency.

Even before you get the sound test certificate, you will receive the results of the test. First, our skilled and competent acoustic engineers give you a verbal result at the site. Then, a written report is sent to you within 24 hours of a working day.

So why do we need Sound Testing on Flats?

When sound resistance (or sound insulation) is high in party walls and floors, the environment is more comfortable for residents as sound affects every aspect of our lives including home/work environment and while relaxing.

Insufficient sound insulation usually causes distress and discomfort while an effective sound insulation system brings about speech privacy and helps to improve relaxation and often helps to improve sleep patterns.  This is one of the several reasons why sound insulation is a key element in building.

If, for example, resident working night shifts may not be able to sleep if their neighbour/s like to play loud music. Robust levels of sound insulation will help to reduce the noise and help to improve the quality of a person’s life in diverse ways. There are also developments where the neighbouring units are used for different purposes, such as home/work/studio units, in such cases a sound test ensures that the noise coming from each unit is minimal.

Why Choose us for your Acoustic Requirements

APT Sound Testing was formed with the idea of offering clients all the necessary help with acoustics on their projects. We provide all the necessary noise assessments, testing and certification under one roof to save developers time and money and reduce coordination issues.  Everyone at APT is fully trained and highly knowledgeable in our field or expertise cancelling out any need to speak to multiple people or departments

Based in London and Luton and operating nationwide across England & Wales, whether you require a single service or a fully tailored compliance package from design to sign off stage you can rest assured that APT will take a pro-active approach to ensure you have everything required for Building control sign off.

It is our ongoing our goal to ensure all of our clients and customers are aware of all the required services their project(s) needs. We offer the most cost-effective assessment and precompletion testing solutions for your projects.

We also specialise with failed projects by providing on site diagnostics. If you have failed air tests, sound tests, low EPC ratings or bad ventilation rates are not things to be worried about then please contact us, at APT we have a massive amount of experience in providing the most cost effective and easy to understand remedial solutions.

For further information sound insulation on party floors in Flats, please see our sound test checklist or visit us at www.aptsoundtesting.co.uk or call us on 01525 303905.  

Sound Testing to Minimising Noise Transference
There are many different types of intrusive sounds that can penetrate through external walls, party walls, and separating floors. And these are a major concern for the inhabitants and users of both residential and commercial buildings.

In many existing buildings, where noise is a problem, any noise reduction is welcomed, giving comfort and relief by improving the quality of the living space. In residential building conversions, alterations must be designed to minimise the risk of disturbance from external noise sources from both neighbouring properties or from outside noise sources via the building façade.

Defining Noise

There are many ways to define noise; usually, it’s any unwanted, unpleasant or unexpected loud sound’. Most people will be disturbed by any unexpected loud noise, but many are able to become accustomed and de-sensitised to constant background noises as long as these do not vary in pitch or become too loud or intense. A couple of examples of this are residents living under an airport flight path or adjacent to a railway line.

Noise usually originates from outside the building envelope, via sound sources such as traffic, horns, alarms, and sirens, however, noise can also be generated from within buildings via household activities such as televisions, radios and washing machines or badly maintained mechanical plant. Equipment such as old central heating boilers and air conditioning units can generate significant whine and hum acoustics which can be very upsetting to certain ‘sensitive’ people and can greatly affect the person/s wellbeing. The preferred background (ambient) noise level in dwellings is 35dB. This is very often reduced to 30dB for sleeping areas as this is seen as the most sensitive area within a dwelling.

The subsequent noise intensity is measured in decibel (dB) units and uses a logarithmic scale. A 10dB increase in noise is normally perceived as a ‘doubling’ in loudness. The table below gives the typical decibel level of some example sound sources.

SOUND LEVEL (dB)	DESCRIPTION	SOURCE EXAMPLE
10 20 40-50 50-60 70 80	Very faint Quiet Normal Noisy Loud Very loud	Normal breathing Whisper at 1.0 metre Light traffic at 50 metres Loud speech Busy street, pub or restaurant Vacuum cleaner or hairdryer

Improving Sound Insulation

In order to consider the options for tackling noise problems, it is necessary to have a basic understanding of sound behaviour and acoustic design.

In most instances, the weakest acoustic area of the external walls will be window units. In existing buildings, these are often Sash units and many councils do want them replaced as they are one of the most important features within the external façade of existing buildings.

As a result, many councils/local authorities will not let you remove and replace original window units unless the frames are rotten and beyond reasonable repair, however despite this decent acoustic improvements can still be made by installing a draught-proofing strip to the opening lights, and by providing an acoustic caulk seal around the window frame.

If it’s extremely noise secondary glazing units can be installed along with demountable shutters. One of the simplest improvements can be made via the installation of good quality heavy curtains fixed close to the wall; this can also be one of the most attractive upgrades and can also help keep heat within the home – a double winner!

If the building is being subdivided into new apartments then the walls between apartments will need to be sound tested in line with Part E for Converted Dwellings. In this instance, we can undertake sample sound testing on walls and floors to check the existing sound insulation performance.  

 APT Sound Testing has considerable experience in all matters related to architectural acoustic design and detailing. We can help develop the initial acoustic design from the initial design scheme stage right through to the pre-completion sound testing.

Our approach is robust and does not leave any room for errors using our In-depth knowledge of acoustic materials, construction systems, and Regulations we can provide the following:

1. Sample sound testing to identify the acoustic performance of the existing building to allow for targeted acoustic upgrades.
2. Acoustic testing of existing wall façades to ISO 140-5, to check the existing sound levels so new targeted wall upgrades can be specified.
3. Provision of cost-effective and practical acoustic solutions
4. Thorough understanding of the desired character of the space
5. Specification of External Building Fabric and including walls, doors and windows in order to minimise noise break-in, or break-out for privacy and overall acoustic quality

If you would like more information in regards to acoustic design or sound testing on your project, please contact us now at: info@aptsoundtesting.co.uk or call us direct on 01525 303905.

Sound Insulation in London
London is a major city in the UK containing in excess of 5 million dwellings. In this overcrowded and often noisy environment, it is essential that robust acoustic design is incorporated into all new and refurbishment projects from the offset.

To help enforce good acoustic design principles pre-completion sound testing was introduced in July 2003, this resulted in all new build properties and conversions that were built after this date are required 10% of each party wall/floor construction type to be tested.

Sound insulation testing is carried out between pairs of rooms separated by party walls or floors. The two ‘habitable’ areas that usually require sound testing are living rooms and bedrooms, although other rooms can be tested if this is not possible, i.e. kitchen to the bedroom.

APT Sound Testing undertakes UKAS accredited Part E sound testing throughout London and the South East. We have extensive knowledge regarding the way different materials and construction methods can influence the results of a sound test, so we can always offer robust and cost-effective acoustic design advice to ensure your compliance with Part E of Regulations. Our usual road map for design advice is:

1. Site Visits & Precompletion Testing
We offer Acoustic Site Survey Visits to let us view the existing site construction. This allows us to check for potential problem areas such as lightweight blocks that haven’t been used in the existing construction. It also lets us check that the installation teams are installing the acoustic materials as per the manufacturer’s guidelines, thus avoiding crucial onsite mistakes. In our experience, a sound test failure is often due to poor workmanship rather than the actual design. The site survey visits negate the risk of sound test failure.

We also undertake 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 an acoustic design that correlates with the existing construction.

2. Acoustic Design Considerations
a.            Avoid using lightweight blocks in the inner envelope construction as sound will travel along light block-work 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.             Use a high quality resilient acoustic membrane on top of the floor to improve the impact performance of a floor.

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

Defect Diagnosis & Remedial Advice
With over 30 years’ experience in building acoustics, we are able to diagnose the reasons for the sound test failure and recommend a cost-effective solution. Often, the reasons for the partition failure are obvious to the test engineer in which case the advice will be minimal, and subsequently the cost for acoustic design advice will be minimal.

Sometimes, there are more technical issues that require more detailed diagnosis and invasive investigation, such as large amounts of noise flanking due to serious design faults, e.g. the use of lightweight blocks in the construction of apartment development.

Whatever the problem we can usually find an acoustic solution that will satisfy Part E of Building Regulations.

If you have a project that needs acoustic design advice or needs sound insulation testing then please contact us via the APT Sound Testing Website or phone us directly on 01525 303 905 and we should be able to offer you an expedient acoustic solution to help you achieve practical completion.

Designing Buildings to Pass Sound Testing
From the very start of the design phase of a new building, it’s extremely important that careful consideration is given to the acoustic element of the building.

By getting us involved at the start of the design process we can undertake comprehensive acoustic design reviews and ongoing site surveys. We always advocate meeting with the design team at the earliest opportunity to go through all acoustic elements for the building’s design, taking into account the site constraints and the most cost-effective method of achieving Part E of Building Regulations. We try to forward any possible ‘onsite’ construction problems and difficulties in achieving successful acoustic construction and subsequently the sound testing for Part E.

Once we have completed the acoustic design review our services don’t finish there. We provide the site team with ongoing design support and site visits. You will have direct contact with the allocated acoustician from the start of the process through to the successful completion of the project.

Acoustic Design & Onsite Construction
Once the first phase of the building is completed, we can undertake sample sound testing to ensure the acoustic design and onsite construction methods are sufficient to pass Part E sound testing.

When it comes to refurbishment projects i.e. houses converted into flats and/or office blocks into flats we can undertake a sample test of the existing wall and floor construction. Once we have established the sound levels for the existing construction we can then look at the extent of the acoustic upgrades to attain Part E Complaisance. This is much more effective than just forwarding an acoustic design that may be too excessive and expensive when the existing construction is already ‘acoustically’ robust and therefore only needs to improve by a few dB.

One problem we often encounter (without our design input) is that the building marginally fails during the sound test. The potential problem that is often overlooked is that many types of acoustic design/materials have attained an acoustic rating within a laboratory. It is very difficult and extremely unlikely that the sound levels achieved on a construction site will be as good as in the confines of a stringent laboratory environment.

When the construction assembly is tested in the lab, it is also certified and an exact description of the materials and the installation techniques are described in detail and followed to the letter, obviously, this should be replicated on your site as closely as possible, however, this seldom happens. This is one of the reasons why a 5dB point difference is allowed between the construction design on paper and the actual on-site construction performance.

When you consider that sound doubles every 10dB, then 5dB can make a huge difference to the overall performance of the dividing partition under test. If consideration is not allowed during the design process then there will be a greater chance of a sound test failure on your project. 

Another potentially problematic area of sound transference and potential sound test failures is down to flanking sound. Noise flanking is when travels along a continuous path due to insufficient isolation/break within the building wall & floor elements. One of the most common flanking paths is along with the inner leaf of an external cavity wall. This may be due to lightweight block construction resulting insufficient mass to prevent noise transference.  

Unwanted noise travelling along flanking paths makes the building structure vibrate and this causes the sound to radiate into your room. One 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). APT can help to locate the flanking sound and propose a cost-effective design that will pass the sound testing and satisfy Part E of Building Regulations.

For the smaller projects, we undertake a more simplified acoustic design service consisting of a review of the design drawings, such as to floor plans and sections. This usually takes place straight after planning has been approved as increased cost savings can be realised at the earliest stage. We can also undertake sample sound testing if the client is not sure of the existing onsite construction.

We can then evaluate the building design to ensure that it the walls and floors are capable of meeting the acoustic requirements of Approved Document E.

Some of the main areas we consider are:

•             There are no potential flanking points, where isolated partitions are wrongly mechanically fixed together to cause noise bridging or the wrong materials have been specified such as lightweight blocks etc.

•             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 many areas that get missed.

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

•             The Lighting specification to, ensure they are acoustically compliant to the overall design i.e. down lighter design, etc.

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 visit the APT Sound Testing website.

The Required Site Conditions for Sound Insulation Testing
During the sound insulation testing, our equipment produces high levels of noise; between 100-100dB. However, to record accurate test measurements, relatively quiet conditions are required on-site throughout the testing. Any site operatives working in the testing area will have to leave temporarily and any noisy works in the vicinity of the test areas including external site activity such as groundworks, drilling and banging will need to be halted. We also require full access to all the rooms being tested.

We provide a full testing schedule within our quotation which will clearly identify suitable couplings of test rooms that may require access to adjoining neighbours dwellings to enable us to complete the testing. APT Sound Testing will try to schedule the sound testing with you at a time when noise can be controlled to achieve the best possible testing results.

How Long Will the Sound Testing Take?
The time taken to undertake sound testing varies from project to project as no site is exactly the same. Taking into account standard site conditions a set of tests on houses -two airborne walls will take one to two hours. A six-pack of tests on flats – 2 airborne walls, two airborne floors, and two impact tests will take between two to three hours. Throughout the sound testing, we will require full free uninterrupted access to the units/rooms in all test areas.

Should I inform my Neighbours of the Sound Testing?
Your neighbours will need to be contacted if access is required to their properties to complete the sound testing. Also as the sound levels produced during the test are very high it would be ‘neighbourly’ to inform the residents as they are likely to hear the test. If your project is a new build and/or a change of use and it’s built onto an existing property then chances are you will be required to undertake an airborne wall test.  We recommend that you check this with your local building control officer prior to the testing so you can plan access to the neighbouring properties accordingly.

Can I Observe the Sound Testing?
APT Sound Testing will happily give you a brief demonstration and overview of the test if so required; however, during the actual sound testing, we will need to follow stringent rules which restrict extra personnel within the test areas.

I want peace of mind that I’ll pass the sound testing
Poor Sound test results can occur for many reasons. The most common factor influencing acoustic performance is poor workmanship. Detailing is critical to maximising on-site acoustic performance, especially in floor and wall isolation and appropriate party wall and floor construction. If inadequate provision for the isolation of materials is not undertaken Noise flanking may occur which is another common reason for sound test failure.

We offer an acoustic design service to review the construction detailing. We also offer a sample testing service along with site inspections which provides a ‘one-stop acoustic solution’. We visit the site during the build process to check for any workmanship issues that may cause problems during the final pre-completion testing.

If you would like APT Sound Testing to review your site construction or to comment on their suitability, then please speak to us about our acoustic design advice service. This is a relatively inexpensive option that may avoid sound testing failures which result in expensive remedial treatment and delay your project handover.

For information in regards to sound testing or acoustic design, please follow our blog at: http://soundtestinguk.blogspot.co.uk/, or contact us on 0777 5623464 or visit our website at: www.aptsoundtesting.co.uk  

Sound Testing Explained

So what exactly is 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 another 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.

Types of Sound Insulation in Buildings
Approved Document E stipulates that there are two types of sound insulation in buildings: airborne and impact. Airborne sound insulation is used when the 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 that 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 that 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 on 01525 303 905or email us direct at info@aptsoundtesting.co.uk.

Sound Testing for New Build Dwellings
Sound Insulation Testing became mandatory in England & Wales in 2003, when Approved Document E was updated. Approved Document E requires new and converted to achieve a reasonable level of sound insulation between dwellings. The simplest way to comply with the requirements of Approved Document E; is to have on-site pre-completion sound insulation tests carried out on your project. We carry out full sound testing services in compliance with Approved Document E.

In our experience there is usually a level of apprehension with our clients having to undertake pre-completion sound insulation tests.  This is often down to the fear of failure. It should be remembered; however, that if the acoustic design specification is closely followed, and a good standard of onsite workmanship is maintained there is very little chance of failure.

Sound Testing New Build
Approved Document E requires a minimum of one ‘set’ of tests for every ten units in each group and/or sub group.  Is usually broken down to the following: two airborne wall, two airborne floor and two impact sound tests. For example, if you have a block of 100 flats, all of the same construction, you would usually conduct 10 ‘sets’ of tests. If you have a development of 25 houses, with five different sub-groups (5 units in each) then you would usually conduct 5 ‘sets’ of tests.  As previously stated a set of tests usually consists of two airborne tests of separating walls and two airborne tests and two impact tests on separating floors; however, if no separating floors are available, i.e. in semi-detached or terraced houses, one set of tests would consist of two airborne tests of separating walls only.

To test the airborne sound insulation properties of a floor or wall, a sound source which consists of an amplifier and loud speaker is set up on one side of the wall or floor partition that is to be tested. We then turn the setting to turn on Pink noise. Pink noise sounds like the static that can be heard on a radio that is off station or the old TV test card noise.

This type of noise is used because it is made up of a wall of sound that has a wide spectrum of frequencies. This provides an indication of sound insulation performance for a wide range of sounds that may be experienced within a dwelling from speech to a kettle boiling. The pink noise is measured in the room which contains the speaker or sound source using a Class 1 Norsonic sound level meter; thereafter the noise is measured on the other side of the wall or floor partition that is being tested. In layman’s terms the difference between these two levels is the amount of sound that is stopped by the sound insulating qualities if the wall or floor partition/s.

The result is then corrected and adjusted depending on the echo or reverberation time within the receiving room, and any background noise such as builders work noise etc. to give the airborne sound insulation result (DnT,w). The results of these tests are then compared to the performance criteria of Approved Document E – 45dB new build & 62dB for conversions) and a pass or fail sound test certificate is produced

Testing Impact Sound Insulation Performance
To test the impact sound insulation performance of a floor, a Norsonic tapping machine which consists of five small hammers that are dropped onto the floor to simulate foot fall, is placed on the floor. The resultant noise in the room below is measured with a Norsonic Class 1 sound level meter and the amount of noise that passes through the floor is the impact sound transmission level and is expressed as a single number. This result is then corrected and adjusted depending on the reverberation time of the rooms as well as any background noise to give the impact sound transmission result (LnT,w). The results of these tests are then compared to the performance criteria of Approved Document E – 62dB new build & 64dB conversions) and a pass or fail sound testing certificate is produced.

If pre-completion test results do not satisfy the performance criteria of Approved Document E, then our test engineer will attempt to determine the possible causes of failure. This may be to do with construction detailing around services or at junctions, or simply, poor acoustic design. Once the results have been finalised along with the associated graphs, our acoustician (with the aid of the information from the sound test engineer, we should be able to determine the specific cause of failure. Once a specific reason for failure has been determined, we can then advise the client on remedial actions that can be undertaken.

Contact APT Sound Testing
If you have a project that’s needs acoustic design advice or needs pre-completion sound testing then please contact us by visiting the  APT Sound Testing Website and we should be able to offer you an acoustic solution to help your project achieve practical completion.

The Secret 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 are 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 use 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 to 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 to achieve at least 62dB for new build properties and 64dB for conversion developments. Impact insulation performance only applies to party floors and is 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 that 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 projects 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 the inclusion of lightweight blocks in the existing construction. It also lets us check that the installation teams are installing the acoustic materials as per the 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.

Successful Sound Testing with APT
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 poor workmanship rather than the acoustic design that is why we offer a full‘4 step’ acoustic package. 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 07775623464.