Air Pressure, Sound Testing and Air Testing Services UK

Head Office: Sayells Farm, 7 Harlington Road, Upper Sundon, Bedfordshire, LU3 3PE
Tel: 07967 233836 or 07775 623464
Offices in London, Luton and Cardiff

Who We Are

Our Services

Why Air Testing

Why Acoustic Testing

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View Swept Sine Document




Why Acoustic Testing

Sound Insulation Testing (Part E)
Recent changes to The Building Regulations have led to sound insulation testing becoming mandatory throughout residential developments unless Robust Detailing is used. As such you may well have been requested to carry out sound insulation testing by Building Control.
Air Pressure Testing’s sound insulation testing service is built around customer satisfaction, specifically in terms of Speed, flexibility and quality. This is ensured by having a team of highly trained test engineers available at all times utilising the very latest equipment at the forefront of technology. This allows you to carry on with your works without having to shut the site for the duration of the Testing
Please click for swept sine technology.

Air Pressure Testing can undertake all of your insulation testing in accordance with
Approved Document E

Why you should APT for all your part E requirements

• Testing is arranged as soon as possible as we are aware that quick turnaround time is crucial for our clients.
• We offer highly competitive prices Click here for a quote
• We use top quality instrumentation to ensure you get the best service available.

What is Sound Insulation Testing FAQ (frequently asked questions)

What is sound insulation?
Sound insulation is the property of a wall or a floor to resist the passage of noise.
What is sound insulation testing?
Sound Insulation Testing is a method of quantifying the sound insulation performance of a wall or floor. Sound insulation testing can be carried out on party walls, party floors or facades of any building. The methodology For Air Tightness & Sound Insulation Testing is set out in various parts of BS EN ISO 140 and ratings in parts of BS EN ISO 717.

Why do I need sound insulation testing?
The largest single reason for disputes between neighbours is noise complaints. Approved Document Part E - Resistance to the passage of sound of the Building Regulations describes minimum standards to be achieved by newly built domestic dwellings. Sound insulation testing is also required in schools, hospitals and workplaces where noisy activities need to be separated from quiet activities.

The Building Regulations Approved Document Part E sets out minimum standards for sound insulation performance to be achieved by party wall and party floors. Building contractors may show compliance with Part E of the Building Regulations by two methods. One method is to register plots to be built with Robust Standard Details Limited and the other is to show as-built performance by Pre-Completion Testing.
What is Pre-Completion Testing?

Pre-Completion Testing is method of showing compliance with Approved Document Part E of the Building Regulations by testing a construction in-situ prior to handover. Site Measurement Services Ltd offer competitively priced sound insulation testing to both large and small building contractors for any size of development.

What is a Robust Standard Detail?
A Robust Standard Detail is party wall or floor construction of proven performance that is part of the Robust Standard Detail scheme. The Robust Standard Detail scheme is provided by Robust Standard Detail Limited, an organisation that oversees the registration, specification and construction of party wall or floor constructions. RSD Limited produces a handbook containing specifications and checklists for a restricted number of proven constructions based on empirical data. RSD Limited carries out visual inspections during construction of registered plots and spot checks a sample following completion.

When are Pre-Completion Testing sound insulation tests carried out?
Sound insulation testing required for Pre-Completion Testing (PCT) with respect to Building Regulations Approved Document Part E are carried out when the construction of party walls and floors are largely complete. Windows should be in place with any vents closeable. Internal and external doors should be in place, along with skirting, cornicing and plug sockets in place. Sound insulation testing on floors must be carried out before any soft coverings are in place.

Sound insulation testing following noise complaints from residents can be carried out at any time when suitable access can be arranged.
Airborne Sound Insulation is determined by the difference D in sound levels between a source and receiver room. This is corrected for reverberation DnT, and weighted to give a single number value for the Sound Insulation DnT,w + Ctr.

Impact Sound Insulation
Is determined by measuring the sound level L, in the receiver room.
This is corrected for reverberation, L’nT, and weighted to give a single number value for Sound Insulation L’nT,w.

Download an electronic copy of Approved Document E here

Sound Insulation Testing (the facts)

Airborne Sound Insulation
Airborne sound insulation is determined by the difference D in sound levels between a source and receiver room.
This is corrected for reverberation DnT, and weighted to give a single number value for the Sound
Insulation DnT,w+ Ctr.

The loudspeaker in the Source Room emits a loud noise over a range of frequencies (pink noise).
The microphone in the Source and Receiving Room measures the sound pressure level. Using specialist UKAS Calibrated equipment, our acoustician then calculates the airborne sound insulation (DnT,w + Ctr).

Impact Sound Insulation
Impact sound insulation is determined by measuring the sound level L, in the receiver room. This is corrected for reverberation, L'nT, and weighted to give a single number value for Sound Insulation L'nT,w.

In the Source Room a tapping machine impacts repeatedly directly onto the floor structure.
A microphone in the Receiving Room measures the sound pressure level and the recorded level produces the Impact result (L’nT,w).
In order to comply with Approved Document E of the Building Regulations, 10% of plots used in each development for residential purposes should be tested if robust detailing is not used.

Breaking News: Application of new measurement method in building and room acoustics.
The classical methods of determining the sound transmission between rooms have been with us for some time and their limitations are well known mostly due to background noise being too high.

These difficulties are now recognised by the standards authorities and in response they have published the BS EN ISO 18233:2006 Acoustics – “Application of new measurement methods in building and room acoustics”. This standardises measurement procedures based on deterministic signals that can be used to obtain the impulse response of the test space which in turn may be post processed to give both the level difference and reverberation time.

Two methods have been standardised and these may be used as alternatives for the classical methods described in BS EN ISO 140 (all parts) BS EN ISO 3382 (all parts) and ISO 17497-1 when determining the reverberation time or level difference for calculation of sound insulation parameters as per BS EN IEC 717 series of standards

• The MLS method is implemented in the Nor-840 analyser and is best suited to controlled conditions such as test laboratories etc.
• The Swept-sine method described in annexe B is implemented in the Nor-121 analyser and as this is more robust in terms of test environment and resistance to harmonic distortion is recommended for field application impossible at low frequency bands by traditional techniques. This is due to internal decay times of the filters used that limit the shortest possible measurable decay. Norsonic have overcome this problem by the use of reverse filtering with specially crafted filters that both provide short decay times and conform to class 1 requirement of IEC 61260.

Advantages of Swept-sine Compared to MLS:
MLS measurement technique uses a Maximum Length Sequence (MLS) as the excitation signal.
MLS is a deterministic binary sequence with frequency characteristic of white noise. Similar to swept-sine, MLS technique uses deconvolution in the analysis part. analyses, we can conclude that this is the case on the lower frequencies. However this improvement was not enough to obtain correct results at higher frequencies due to prevailing background noise. The swept-sine technique not only provides higher level of excitation but also suppresses the background noise. It can clearly be noted that measured results are under background noise at higher frequencies. Therefore swept-sine is capable of performing the correct measurements even in environments with negative signal to noise ratios, being the only method that could give the correct result in this example, this helps you as we do not require total silence during the Acoustic testing.

A few of the advantages of swept-sine over MLS are

• Immunity against harmonic distortion?
• Higher excitation level might be used
• Robustness against time variance?

With swept-sine techniques higher loudspeaker output levels can be used. This will result in higher level of excitation signal (highly desirable feature as it increases SNR) but may also cause harmonic distortion due to the non-linearity of the loudspeaker. This distortion will appear in impulse responses obtained by MLS and swept-sine in two different ways. In an MLS measured response, the distortion will appear as spurious peaks. This reduces the SNR and may deteriorate the measured IR in such an extent that it limits the applications. On the other hand, when the impulse response is measured with the swept-sine technique, the effects of harmonic distortion can be completely removed. Use of linear deconvolution makes distortion components appearing at the “negative” times in measured impulse response and these components can be removed by windowing. This useful feature also makes it possible to reduce the size and weight of the excitation loudspeaker, this helps when you are Acoustic testing a new build which is abutted to an existing building, as the adjacent owners may complain about the noise levels during the Acoustic test

Robustness Against comparison on those decays leads to no noticeable increase of background noise level, which leads to conclusion that swept-sine is the method of choice for outdoor and insulation testing

Checklist of Items to be completed prior to our arrival on Site to undertake the Acoustic Test

The best time to carry out sound testing is towards the completion of the project, but before the floor finishes have been applied. In addition the optimum conditions are when the site is quiet. If there is noise on the site from equipment and 'on going works' there is an increased chance of a sound test failure.

Housing developers and/or site managers will have to nominate a day for testing and restrict any noisy activity during the tests. The following list provides an indicative checklist for site managers for the requirements of the plots and sites where testing may be carried out.

1. We require accurately dimensioned floor plan layout drawings of the rooms to be tested; AT LEAST 5 WORKING DAYS before the test date.

2. We require a 240v Mains Electric socket in each of the rooms being tested.

3. We will require a clean & quiet working environment for our testing works.

4. Ensure that the completed building envelope is finished. All doors, windows, and cladding must be installed. Make sure that:

- Windows are fully fitted with locks in place.
- Window trickle vents are in place or temporarily blocked up for testing.
- Individual room and front doors are in place and closable.
- All wall surfaces in rooms to be tested are complete (including sockets and switches if applicable).
- Floor and ceiling surface are complete.
- Carpets or timber laminates have NOT been laid in rooms where floors are to be tested (with the exception of bonded carpet)

5. All of the rooms to be tested will need to be cleared of materials & operatives during the testing.

6. Seal all ducts and penetrations where the main services enter the building.

7. Lift shaft doors are to be kept closed.

8. On our quotation a time is allowed for the test. If, due to the site not being prepared adequately, or the test over runs due to reasons beyond our control, our extra hourly charges would be as stated on our quotation.

9. Have a competent member of your staff available on the test day to ensure that the above items remain in place during the testing period.

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