Good Acoustic Design Detailing

Good Acoustic Design Detailing.

Careful consideration to acoustic design detailing should be used from the offset of the project, whether it’s a new build or conversion project, 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.

architect drafting a house blueprint

To help our clients achieve a successful sound test at the first attempt, we offer a full acoustic package which consists of the following elements:

  • Site Survey Visits – to let us view the existing site construction. This allows us to check for potential problematic construction such as inclusion of lightweight blocks in the existing construction. It also lets us check that the installation teams are installing the acoustic materials as per manufacturer’s guidelines.
  • 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.
  • Acoustic Design Review – a full design review of the proposed developments party walls and floors.

There are many design considerations that need to be accounted for when allowing for your project/s, they are:

  • Avoid the use of lightweight blocks in the inner envelope construction as sound will travel both vertically and horizontally from dwelling to dwelling.
  • The use of resilient suspended ceilings will help improve the performance of the floor partition.
  • Ensure all support steels/timbers are carefully boxed out where they travel from flat to flat vertically and horizontally.
  • Use a high quality resilient acoustic membrane on top of the floor to improve the impact performance of a floor.
  • Ensure all penetrations are fully sealed where they terminate through floors and they are adequately boxed with acoustic quilt and two layers of plasterboard.

If you have a project that’s needs acoustic design advice or sound testing in London, then please contact us at: info@aptsoundtesting.co.uk or phone us directly on 07775623464.

How Is Sound Insulation Testing Carried Out?

How Is Sound Insulation Testing Carried Out?

For airborne wall and floor sound tests, two individual speaker positions are used for each source room; with a total of ten individual 1/3 octave band measurements recorded for both the source and receiver rooms. Measurements are then made to monitor the levels in the receiving room of the tested partition in question. This gives a basic level difference between source and receiver rooms.

Sound_Insulation_Testing_Equipment

This basic level difference is then ‘corrected’ to allow for the reverberation time (the time taken, in seconds, for a noise source to decay by 60 dB) and the existing levels of background noise monitored whilst in the receiving room.

All our tests are carried out in full accordance with BS EN ISO 140-1998 parts 4 (airborne sound testing) and 7 (impact sound testing), and the calculation of all single figure results are done so in accordance with BS EN ISO 717:1.

How do I know when my site is ready for testing?

Sound testing is typically conducted when a development nears completion, and once all internal and external doors and windows have been fitted, it is worth noting that no carpets should be installed prior to the sound testing.

To be able to conduct sound insulation testing we a constant supply of 240V power; we cannot use generator power. We also require a quiet site (a noisy site can make conducting the tests extremely difficult), so no drilling, jack hammers etc. should be used whilst the testing is taking place. We also require full access to all rooms to either side of the dividing partition so if it is a requirement to access a neighbour’s property, this must be arranged prior to the test date.

If you require a sound insulation test than contact us know, we will explain what the test entails and send you our informative checklist to help you prepare for the test. It is our mission to ensure our clients pass their testing at the first attempt. We pride ourselves on providing a ‘one stop acoustic solution’ for all your acoustic requirements.

If you would like more information in regards to our acoustic services, including acoustic design reviews, sound testing and noise surveys please contact us at: info@aptsoundtesting.co.uk or call Darren on 07775623464 or visit our website at: www.aptsoundtesting.co.uk

 

 

 

Approved Document E: Frequently Asked Questions

Approved Document E: Frequently Asked Questions

Why am I required to undertake sound insulation testing?  

Sound insulation and speech privacy are critical for a variety of reasons. Inadequate sound insulation can be extremely distressing to those affected by it and may lead no major noise disputes and legal actions. For example, in an apartment block, your upstairs neighbour may like playing loud music. However, the downstairs occupant may be working nights and sleeping throughout the day, thus any inadequate sound insulation between these two flats would cause great disturbance and distress to the downstairs occupants.

Noise_Problems_Failed_Sound_Testing

 What is precompletion sound insulation testing?

Precompletion sound testing is a building regulation requirement for all new build and dwellings formed by ‘material change of use”, i.e. conversion projects. It has been a requirement that you undertake sound testing on dwellings since 2003. Sound testing should be undertaken to 10% of properties in each development to ensure that the separating walls & floors between habitable rooms of neighbouring properties meet the minimum requirements as defined by Approved Document E, commonly referred to as Approved Document E; for instance:

  • For a pair of semi-detached Houses – a set of tests would usually comprise two airborne sound insulation tests of a separating wall.
  • For Flats (up to 10 units) – a six pack would normally be required, this comprises of: two airborne wall tests, two airborne floor tests and two impact floor sound tests. The easiest way to work out the number of tests required is to multiply 1 x 6 packs for every 10 flats, i.e. if you have 22 flats you will require 3 x 6 packs which equals 18 sound tests in total.
  • For Rooms for Residential Purposes (up to 10 rooms) (student accommodation, hotel rooms, care homes etc.) – a set of tests would usually comprise: one airborne sound insulation tests of a separating wall; one airborne sound insulation test of a separating floor; one impact sound transmission test of a separating floor.

Sound_Testing_Flats

If you would like more information on our full range of our acoustic services, including sound testing, acoustic design and noise surveys, please contact us now at info@aptsoundtesting.co.uk or call Darren direct on 07775 623464.

Noise Flanking Paths

Noise Flanking Paths

To reduce the chance of sound testing failure, it is imperative that flanking transmission is considered at the design stage to reduce potential noise flanking paths. Good detailing at the design stage will minimise this effect and optimise the overall levels of acoustic privacy achieved. If designing for residential units, design advice on flanking details must be followed to maximise the possibility of achieving the specified acoustic performance. It is imperative that the design advice is followed, otherwise the site sound insulation values may not meet the performance criteria required and subsequent expensive remedial treatment may be required.

sound_transmission_through_floors

Flanking sound is defined as sound from a source room that is not transmitted via the separating building element e.g. the wall or floor partition. The sound is transmitted indirectly via paths such as external walls, windows, doors and internal corridors. One of the easiest ways of dealing with sound flanking issues is to use isolation strips around the perimeter of the partitions at the edges of floors and walls, this should be finished with acoustic sealant

One of the main reasons for flanking sound test failures is when the inner leaf of the perimeter wall is built with light weight blocks. This acts like a large snare drum and the sound simple travels straight up the wall from one flat to the flat above and/or below. Even if you have used a acoustically robust wall and/or floor partition the sound insulation testing may still fail. If you have used lightweight blocks in your onsite construction and the building fails the sound test you may need to construction independent internal plasterboard lining throughout the inner perimeter wall, this should isolate the lightweight blocks and ensure the flanking path is minimized.

If the onsite construction has gaps, cracks or holes it will conduct airborne sounds and can significantly reduce the sound insulation of a construction. For optimum sound insulation a construction must be airtight. Most small gaps can be sealed at the finishing stage using Gyproc jointing compounds. Small gaps or air paths around perimeter Gypframe framework can be sealed with sealant. At the base of the partition, gaps will occur which can be filled with acoustic mastic.

If you would like more information in regards to sound insulation testing and or acoustic design advice, then please call us now at info@airpressuretesting.net or call me (Darren) direct on 07775623464.

Sound Testing Rating Methods

Sound Testing Rating Methods

Sound tests are broken down into various sound testing rating methods. The sound insulation definition and terms are as follows:

Rating Method – RW

This single figure rating method is the rating used for laboratory airborne sound insulation tests. The figure indicates the amount of sound energy being stopped by a separating building element when tested in isolation in the absence of any flanking paths.

Acoustic_Design_Service

Rating Method – DnTw

The single figure rating method that gives the airborne sound insulation performance between two adjacent rooms within a building as measured within site conditions. The result achieved is affected not only by the separating element also by the surrounding structure and junction details.

Rating Method – Ctr

The Ctr adaptation term is a correction that can be added to either the RW (laboratory) or DnTw (site) airborne rating. The Ctr term is used because it targets the low frequency performance of a building element and in particular the performance achieved in the 100 – 315 Hz frequency range. This term was originally developed to describe how a building element would perform if subject to excessive low frequency sound sources, such as traffic and railway noise. This rating is expressed as RW + Ctr and allows the acoustic designer to critically compare performances. The rating method has not been universally welcomed. Some acoustician believe that the method is too crude as it only considers the low frequency performance, and because site measurements at low frequencies are prone to difficulties, which can lead to a lack of confidence in the results achieved.

Rating Method – Lnw

This single figure rating method is the rating used for laboratory impact sound insulation tests on separating floors. The figure indicates the amount of sound energy being transmitted through the floor tested in isolation, in the absence of any flanking paths. With impact sound insulation, the lower the figure the better the performance.

Rating Method – LnTw

The single figure rating method that is used for impact sound insulation tests for floors. The figure indicates the sound insulation performance between two adjacent rooms within a building as measured on site. The result achieved is affected not only by the separating floor but also by the surrounding structure, e.g. flanking walls and associated junction details.

Rating Method – Dncw

This is a single figure laboratory rating method, which is used for evaluating the airborne sound insulation performance of suspended ceilings. Laboratory tests simulate the room-to-room performance of the suspended ceiling when a partition is built up to the underside of the ceiling with sound transmitted via the plenum.

If you have a project that’s needs acoustic design advice or sound insulation testing, then please contact us at: info@aptsoundtesting.co.uk or phone me (Darren) directly on 07775623464.

Sound Test Procedure

Sound Test Procedure 

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.

Sound_Insulation_Testing_Equipment

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.

We offer both pre-construction acoustic design advice and  we can also help if your building has failed the Part E sound test. We also offer onsite inspection services to ensure that the sound insulation elements are being installed as per manufactures guild-lines.

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

Sound Intrusion Though Windows

Sound Intrusion Though Windows

Sound intrusion though windows can also be a source of great annoyance if the sound is excessive, and in some cases developments have failed the sound insulation testing due to poorly specified and installed windows. Sound intrusion may be down to a variety of factors. If the windows are operable types, the first thing to check is to see if the widows close properly against their seals and any weather stripping is continuous and in good order. If the window leaks air, then more often than not it will usually leak sound. If the window closes to form a tight seal and the weather-stripping seems adequate the next thing to check is the window frame. Windows are frequently installed in to the wall opening with plastic shims to insure the unit is plumb and level. In high traffic areas you will normally require a double glazed unit as a minimum and in some cases a triple glazed unit will be required.

Sound_Intrusion_Through_Windows

The space between the frame and the wall should be insulated and sealed before the window casings are installed. If this was not done correctly you can probably detect the sound leakage by placing your ear close to the frame and listening. The sound may be able to run along the cavity and back into the adjacent property, It is case of letting your ears do the walking and listening. If you detect distinguishable differences in sound you may have found the problem; the solution will be to remove the casing and insulate and caulk all leaks. In some cases the thickness of the glass maybe the problem in which case it may be necessary to install another layer of glass on the inside of the existing frame making sure that the additional pane of glass is well sealed into the opening.

In some instances you may be able to lower excessive sound by installing a heavy curtain – especially if the house is in a conservation area and as a result the local authority will not let you change or upgrade the windows.

If you require more advice on your project and/or you require precompletion sound testing, please contact us at: info@aptsoundtesting.co.uk  or phone me directly on 07775623464.

Remedial action following a sound insulation test failure

Remedial action following a sound insulation test failure

If a partition fails a sound insulation test, it can be difficult to provide definitive guidance on resolving specific problems that have occurred in individual buildings as the building is usually complete at the time of testing. However, using our knowledge of acoustic construction and detailing APT Sound Testing are usually able to identify and resolve any problems with the acoustic partitions.

ACOUSTIC_DESIGN

If the sound testing failure is attributed to the construction of the separating and/or associated flanking elements, other rooms that have not been tested as part of the testing schedule may also fail to meet the test performance levels. Additional tests may be needed, over and above the number recommended under Building Regulations Part E.

Extra sound testing will assist in identifying, at an early stage, where the failures have been caused by intermittent poor workmanship and/or design. Sound Testing may then be required for all plots to identify the ones that require remedial treatment. Where failure is due to a design fault, additional testing may not be required, as all plots with the same design are likely to require remedial treatment and so a generic acoustic upgrade can be undertaken to the failed partitions and then retested thereafter.

sound testing

To try and negate potential problems with the sound insulation testing we offer the following 4 step acoustic design advice package:

  1. Site Survey Visits – to let us view the existing site construction. This allows us to check for potential problematic construction detailing and also lets us check that the installation teams are installing the acoustic materials as per manufacturer’s guidelines.
  2. Sample Sound Testing – of the existing construction. This offers an accurate overview of the acoustic performance of the existing partitions.
  3. Design Review – a full design review of the proposed developments party walls and floors.
  4. Pre-completion Sound Testing to satisfy Approved Document E.

APT Sound Testing can supply a ‘one stop’ solution for all your acoustic requirements. If you would like more information in regards to sound insulation testing or acoustic design please contact us at: info@aptsoundtesting.co.uk  or call Darren direct on 07775623464.

Preparing for your site for Sound Testing

Preparing for your site for Sound Testing

To record accurate test measurements, we need to ensure that the correct site conditions are achieved prior to the precompletion sound testing. 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, otherwise it may result in a sound test failure.  We always provide a full sound testing checklist within our quotation which identifies what actions need to be undertaken prior to the sound test.

sound testing equipment

The condition the buildings/dwelling is very important, as they can influence the results of the test. The following stages for sound testing will help preparation and also assess the point at which completed buildings can be tested. Generally before the test the parts of the building/rooms either side of the separating wall or separating floor should be complete. Particular attention should be paid to the following:

  1. All separating floors and walls and all flanking walls and floors should be complete.
  2. All wall and floor junctions should be complete – to include flanking strips etc.
  3. All wall finishes should be complete, this should include skirting’s being in place. This does not include decorative finishes such as paint.
  4. Floors must be bare and no carpets should be laid – where a concrete floor with bonded resilient cover is to be fitted with wood based flooring. In this case, the test sample resilient floor cover should be tested with a wood based floor covering laid over the test sample area.
  5. Windows should be installed with all glass fitted.
  6. Trickle vents should be in place and closed.
  7. All doors should be fully fitted and closed. This includes internal doors and external doors fully fitted with doors seals.
  8. Services should be complete and any voids around ducts finished.
  9. Electrical sockets should be fitted.
  10. A 240V electricity supply should be available to all the test plots.
  11. There should be no noise during the test other than from the testing equipment.
  12. The test plots and adjacent areas within the building should be quiet for the duration of the test.
  13. No work should be carried out or noise made in the building at the time of the test.
  14. Site workers should not enter the building or be in the parts of the building undergoing a test.

We try to offer a ‘one stop acoustic solution’ visa our acoustic design service, sample sound testing and site visits.

If you would like APT Sound Testing to review your sites acoustic construction, then please speak to us about our acoustic design service, alternatively if you just require sound insulation testing please contact us at: info@aptsoundtesting.co.uk

Simple Acoustic Upgrades

Simple Acoustic Upgrades

There are many simple acoustic upgrades you can undertake to improve the sound insulation values of your dwelling. Plate A below shows one cost effective ceiling upgrade that can be undertaken on conversion projects. Firstly retain the existing floor joists – check them for general wear and tare) then above the joists install 22mm chipboard. Above the floor board install an acoustic resilient membrane and above this install the 22mm engineered floor. Within the joist cavity install 100mm AW IsoWool. To the underside of the joists fix a resilient hanger system and below this install two layers of 12.5mm sound boards ensuring that boards have adequate laps. It is worth noting that although the above system should work, it is essential that you contact us before going ahead with any works as each project is different and may require extra acoustic design input.

Plate A – Acoustic Floor Upgrade

Good Conversion Diagram - 15-01-16Also, to try and help our clients achieve compliance with Approved Document E at the first attempt we offer the following 4 step acoustic design package:

  1. Site Survey Visits – to let us view the existing site construction. This allows us to check for potential problematic construction such as inclusion of lightweight blocks in the existing construction. It also lets us check that the installation teams are installing the acoustic materials as per manufacturer’s guidelines.
  2. Sample Sound Testing – of the existing construction. This offers an accurate overview of the acoustic performance of the existing partitions which enables us to offer a targeted acoustic design using the sound insulation performance of the existing construction.
  3. Acoustic Design Review – a full design review of the proposed developments party walls and floors.
  4. Pre-completion Sound Testing to satisfy Approved Document E.

APT Sound Testing can advise on all types of acoustic design, whether it’s accomplished during initial construction or during a refurbishment/renovation project. We also undertake UKAS accredited sound insulation testing providing a ‘one stop’ solution for all your acoustic requirements.

If you would like more information in regards to sound testing please follow our blog at: http://soundtestinguk.blogspot.co.uk or contact us at: info@aptsoundtesting.co.uk and 07775623464 or visit our website at: www.aptsoundtesting.co.uk