Sound Testing

Building regulations Part E require that buildings are to be tested prior to completion in order to confirm they meet or exceed Part E standards. The person carrying out the building work should arrange for sound insulation testing to be carried out by a test body with approved qualifications and affiliations. All tests are at the Building Inspectors discretion. Failure in the test will result in the sound insulation needing to be improved and the construction type re-tested.

We have the necessary onsite experience and qualifications to carry out the required sound testing on a new build or conversion project for a very competitive price. All our engineers carry out the sound test measurements in compliance with the current British Standard: The airborne and impact sound insulation tests carried out in full accordance with the measurement procedures of BS EN ISO140-4:1998 for field measurements with a single figure DnTw and LnTw in accordance with BS EN ISO 717. As per the new regulations the Spectrum Adaptation Ctr which is a correction factor calculated from the measured DnT.w and the corresponding third octave band DnT values.  It uses a set of weighting levels in third octave bands derived from a road traffic noise spectrum.  It is applied to airborne test results and is measured in dB. A new standard BS EN ISO 16283-1&2:2014 will be replacing ISO 140 for building regulation measurements in due course.

Sound testing procedure is quite 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. Calculations are done based on these measurement and the above mentioned parameters are calculated and compared to the Building Regulations Part E sound insulation requirements for the given type of the building. It is important that the building to be sound tested is completely finished and sealed with no sound leakage through doors and windows.  Please see our check list for sound testing for more information. Watch a brief video showing the process of sound insulation testing.

Do you need a sound test?

We have more than 15 years of experience and have successfully sound tested and certified more than 3000 projects spread across London and the Home Counties and Southeast England. We can advice on best methods and materials to achieve the required standard with minimal use of expensive specialist materials to keep your project within budget.

Approved Document E is split into eight sections. Sections E2 to E8 of the document gives examples of constructions which if built correctly should achieve the sound insulation values set out in Table 1a and Table 1b.

Key Summary of Pre Completion Sound Testing

• The new regulations require that buildings are to be tested prior to completion in order to confirm they meet or exceed Part E standards.
• The Regulations require that one in ten of each construction type require testing.
• The person carrying out the building work should arrange for sound insulation testing to be carried out by a test body with approved qualifications and affiliations.
• All tests are at the Building Inspectors discretion.
• Failure in the test will result in the sound insulation needing to be improved and the construction type re-tested.
Full details of pre-completion testing are explained in Section 1 of the Approved Document.

Who is affected?

• Buildings where there has been a change of use relating to conversions and refurbishments – Effective from 1st July 2003.
• New build houses and flats – Effective from 1st January 2004.
• Domestic Extensions.

Approved Document E is split into four sections
E1 – Protection against sound from other parts of the building and adjoining buildings.
E2 – Protection against sound within a dwelling/house etc
E3 – Reverberation in the common internal parts of buildings containing flats or rooms for residential purposes
E4 – Acoustic Conditions in Schools

E1 and E2 of the document gives examples of constructions which if built correctly should achieve the sound insulation values set out in Table 1a and Table 1b below.

Table 1a: Dwellings-houses and flats – performance standards for separating walls,
separating floors, and stairs that have a separating function.

Description of Area Airborne
Sound Insulation
DnT,w + Ctr dB
(Minimum Values)
Impact
Sound Insulation
L’nT,w dB
(Maximum Values)
Purpose built dwelling-houses and flats
Walls
Floors and stairs
45
45

62
Dwelling-houses and flats formed by material change of use
Walls
Floors and stairs
43
43

64

Table 1b: Rooms for residential purposes – performance standards for separating walls,
separating floors, and stairs that have a separating function.

Description of Area Airborne
Sound Insulation
DnT,w + Ctr dB
(Minimum Values)
Impact
Sound Insulation
L’nT,w dB
(Maximum Values)
Purpose built dwelling-houses and flats
Walls
Floors and stairs
43
45

62
Dwelling-houses and flats formed by material change of use
Walls
Floors and stairs
43
43

64

E3: Reverberation in the common parts of buildings containing flats or rooms for residential purposes
A new requirement to control reverberation in the common parts of buildings containing flats and ‘rooms for residential purposes’. Pre-completion site testing is not required. To satisfy Requirement E3, sound absorption measures described in Section 7 of the Approved Document will need to be followed.

E4: Acoustic conditions in schools
New schools are now controlled under the Building Regulations. This includes sound insulation, reverberation time and indoor ambient noise levels. The normal way of satisfying requirement E4 will be to meet the BB93 values for sound insulation, reverberation time and internal ambient noise.

Major cause of sound test failure is Flanking Transmission: It is important that measures to eliminate or minimise flanking sound transmission are employed at the design stage and the builder installs the specified products correctly. Failure to do so may lead to limitation of acoustic performance and the requirements of the Building Regulations not being met. When attempting to make any sort of construction compliant to the Part E Regulations, it is important to note that sound does not always go straight through the building element. If the wall or floor concerned has good sound reducing capabilities then the sound will simply find the easiest way around it. In short, if the sound can’t go through the wall, it will go up and over or around the side. This is called Flanking Transmission and occurs when sound travels along elements shared by adjacent structures. If measures to tackle Flanking are not correctly specified or constructed, Flanking Transmission can exceed direct transmission and damage the overall capabilities of the construction. One way of dealing with this issue is to use isolation strips around the perimeter edges of floors and walls, as well as the use of an acoustic sealant wherever possible. If the inner leaf of the perimeter wall is built with light weight block, independent internal plasterboard lining throughout will ensure that the flanking path is minimised.

Call us on 020 8300 3092 or send an e mail to discuss your requirements