How to Improve your Sound Test Results

How to improve your Sound Test Results

If you have started a new or conversion development, it is important that from the offset you realise that you will need to comply with stringent sound insulation requirements of Approved Document E. Both new and converted residential dwellings use must meet the standards stipulated in Approved Document E. Part E states that the separating floor partition (floor between two separate dwellings) must achieve sound insulation figures of 45dB for airborne sound and 62dB for impact sound on all new builds and 43dB for airborne sound and 64dB for impact sound on converted dwellings; if you don’t achieve the aforementioned results then you will pass the sound testing. 

Building Control will expect you to demonstrate compliance with Approved Document E 2003 by undertaking an independent sound insulation test to prove that you have met the standards for sound insulation between dwellings.

Sound_Insulation_Testing_Equipment

The sound testing must only be carried out by either UKAS or ANC approved companies. If the sound tests are not carried out by approved compaines then Building Control may not accept the sound test report and subsequently it may need to be undertaken again by an approved company costing more time and money.

We are UKAS accredited to undertake sound insulation testing as well as air tightness testing. We offer design advice to help our client achieve Part E sign off. In some cases clients instruct us to proceed with the sound testing, without having carried our any acoustic upgrades or remedial works often resulting in their partitions failing the sound test.

Sound_Testing_Semi_Detached_House

If you are worried about passing your sound testing in London at the first attempt please don’t hesitate to contact us now at: info@aptsoundtesting.co.uk or visit our website at: www.aptsoundtesting.co.uk or call Darren Direct on 07775623464.

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.

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

Acoustic Design Advice

Acoustic Design Advice

To try and help our clients achieve compliance with Approved Document E, 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 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.

ACOUSTIC_DESIGN

There are many factors to consider when considering good acoustic design, and they are usually split up into five key factors. If used together or in various combinations they will improve sound insulation properties over a wide range of frequencies. The main factors are:

  1. Mass
  2. Isolation
  3. Absorption
  4. Resilience
  5. Stiffness

Also, noise flanking transmission may in some cases be the dominant pathway between adjoining dwellings, especially in existing buildings where you are planning to convert offices/large houses into flats. Here are just a few of the potential noise flanking areas:

  1. Structural Steels
  2. Windows built very close to Internal partitions
  3. Inner leaf of the external wall
  4. External wall cavities
  5. External façade or outer leaf
  6. Roof structure

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 contact us at: info@aptsoundtesting.co.uk or 07775623464 or visit our website at: www.aptsoundtesting.co.uk

Sound Insulation Testing

Sound Insulation Testing

At APT we offer Airborne and Impact Sound Insulation Testing in accordance with Part E of the Building Regulations and, where required sound testing on Schools BB93 & BREEAM. Under Part E of Building Regulations, this is a requirement for new and converted dwellings where there is a separating partition wall or floor. The sound insulation testing of existing buildings is carried out to assess current levels of sound insulation and to allow for the design of remedial measures, where the performance needs to be increased.

The buildings that currently require sound testing are:

  1. Dwelling-houses, flats or rooms for residential purposes created by conversion of existing buildings or new build rooms for residential purposes will need to be tested if work starts after 1 July 2004.
  2. New build dwelling-houses and flats will need to be tested if work starts after 1 July 2004.

Sound insulation testing is carried out to ensure that minimum standards of sound resistance have been met to ensure the well-being of new tenants is not compromised by adverse sound transmission. The testing checks that the dividing partitions have not been compromised by poor workmanship and poor design. We use the latest sound testing equipment as shown below:

sound testing equipment

You are normally required to undertake sound testing to each type of construction, i.e. if you have a mixture of brick, block-work, timber and metal stud-work walls all four types would need to be tested, followed by a 10% sample of that type. it is worth noting that if any test failures occur, then the number of sound tests may need to increase on the development.

If you are unsure whether the Regulations apply to your development or if your site needs sound insulation testing, please call your local office or email us at info@aptsoundtesting.co.uk where our team will be happy to discuss all aspects of acoustics or sound insulation within buildings, and explain the testing procedure.

Adding Mass to Improve Sound Insulation

Adding Mass to Improve Sound Insulation

Adding mass to improve sound insulation can be one of the most important elements to improving precompletion sound testing results. In summary it basically means you add extra weight/mass to the construction of the acoustic wall and/or floor partition. Materials such as solid block-work masonry is best for wall construction; however it is very important that the block-work envelope is constructed out of solid concrete block work as the use of lightweight block work often ends in sound test failure.

Sound_Insulation_Test_London

 For floor construction, solid concrete floors – min 150mm) are usually the best construction for outright mass; however soundboard, plywood and OSB can be found fairly cheaply and will also do the job – if installed as per manufacturer’s guidelines. It is very important that adequate site supervision is on hand to check the construction of all acoustic partitions.

It is basic physics, so for sound to conduct through a wall, it has to actually move (vibrate) the wall ever so slightly. As a heavier wall is harder to move than a lighter wall then it should vibrate less and turn let through less noise. Soundboard is one of the lowest cost sources of mass available and also one of the most commonly used. Wherever possible its best to use two layers of 12.5mm board with the correct laps to the boards. Although the wall will still vibrate it will be less due to the extra mass.

It’s worth noting that although the added mass improved things and it will be more difficult for sound to move this heavier wall, in many instances you will still hear low frequencies (bass noise) quite easily.

Our next blog covers the last – but not least) element of acoustic design – Damping. If you would like more information in regards to acoustic design and sound insulation testing, please contact us now at info@aptsoundtesting.co.uk or call Darren direct on 07775623464.

Noise Absorption

Noise Absorption

It is usual for air cavities to resonate, such as the cavity within a timber wall. For instance if you blow across the top of a bottle and heard the sound, it sounds much louder; this is the trapped air resonating. In a similar way a hollow wall will also trap air that will resonate. When the wall is vibrated by loud sound such as a neighbour’s loud music of TV, the air in the wall cavity will vibrate just like a drum. Unfortunately this air cavity is another means for sound vibration to travel from one side of the acoustic partition wall to the other. So even though the wall framing may be decoupled, the vibrating air cavity may still transmit some sound through the wall between the wall studs. Acoustic fiberglass insulation will absorb some of this (absorption).

installing_acoustic_wool

In all instances acoustic Insulation should help the overall sound insulation test result, and should always be installed if possible. Although the vibration reduction is smaller than the other 3 elements it is still very important.  The key is to keep the density low, so don’t try to compress or pack the insulation as the vibration may use this to bridge the construction.

So to summarise we have now managed to de-couple and insulated the acoustic wall framing, which has helped to stop much of the vibration, but unfortunately not all of it. So what else can we do? – add mass of course. A full explanation of how mass can help your sound test results can be found in the next blog.

If you require any information on our acoustic design and/or sound test services, please contact us at info@aptsoundtesting.co.uk or call Darren on 07775623464.

Decoupling of Materials

Decoupling of Materials

There are many things to consider with your acoustic design and construction, one of the first – and most important) is the decoupling of materials or also know as isolation of materials. Sound travels easily along direct construction pathways, i.e. if the construction is made up of a wooden wall frame with a layer of plasterboard fixed to either side, with this type of construction the sound has a solid mass of materials to travel across. If we “decouple the materials” it reduces the pathway for vibration and the sound levels drop accordingly.

When we design for acoustic partition construction we obviously want less sound vibration to travel from one side of the wall to the other. It is therefore hugely beneficial if we can decouple the partition framing in our walls and ceilings. Decoupling is a simple, inexpensive and highly effective way to improve the sound insulation results for Building Regulations Part E.  .

There are many types of decoupled construction that in turn offer varying degrees of separation of the drywall on one side from the drywall on the other side. For instance the image below shows a twin wall construction which is far superior to a single stud wall. if you require good sound test results, this is one of the best types of construction.

decoupled_wall_construction

By decoupling the wall studs limits by providing a cavity or break between the two walls reduces the vibration trying to conduct through the wall. although this will improves the airborne results, other improvements will still be required.  So although our decoupled framing system reduces a good deal of vibration, we need to continue to the other 3 elements, absorption, mass, and to damping to reduce the noise more effectively.

Our next blog will consider absorption and how it can make a  large difference to sound test results. If you would like more information to acoustic design and/or sound insulation testing please contact us at: info@aptsoundtesting.co.uk or call Darren on 07775623464.

The Main Sound Proofing Elements

The main Sound Proofing Elements

Coupled Wall Construction

We often get asked ‘how can we improve our soundproofing on our development. The first thing to understand is the basic of soundproofing design and construction. If you understand the basics, you’ll have a more educated view point in regards to the way sound and vibration behaves within your new dwellings. Basically, we want to stop sound and vibration through the walls and floors of your development and one of the best ways of doing this is avoiding coupled wall construction. In general, we are trying to stop vibrations from getting to “your” side of the wall or ceiling.

The plate below shows a typical wall and noise problems associated with it. With this type of construction noise transference is a big problem. If there is even moderate levels of noise on one side of the wall the chances are you will hear it.

coupled_wall_construction

If you look at the red arrows in the above diagram it clearly shows how sound is conducted from one side of the wall to the other. As the wall elements are firmly fixed against each other, i.e. the plasterboard is rigidly connected to the timber, the vibration conducts straight through the whole wall construction.

If you look at the blue waves this indicates airborne transmission. The plasterboard is vibrating back and forth which produces a sound wave in the wall cavity. This, in turn, vibrates the plasterboard on the opposite side of the wall. the whole construction acts like a  huge diaphragm or like a large speaker with both sides of the wall vibrating in unison, which is not ideal.

Our next blog will explain how we can reduce noise transmission by decoupling the wall construction. if you would like more information on our sound testing or acoustic design services please contact us now at: info@aptsoundtesting.co.uk or call Darren direct on 07775623464.

Sound Transmission Though Windows

Sound Transmission Though Windows

One source of great annoyance is often due to sound transmission though windows, this can 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.

Noise_Problems_Failed_Sound_Testing

Windows are frequently installed in to the wall opening with plastic shims to insure the unit is plumb and level. 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.

Usually double pane windows have poor noise-stopping capabilities. This may be overcome by installing a layer of lamination. Many manufacturers offer this service but it can be quite costly. Although double pane windows do stop a bit more noise than single pane windows it is still not very effective. In a noisy environment, you would hardly notice the difference.

Part of the problem is down to the construction of double pane windows; this is because the two pieces of glass are coupled within the same frame and vibrate together, similar to a tuning fork. Sound insulation, however, is increased markedly by using a double pane system and replacing air by argon between the panes.

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.

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