Sound Insulation Testing in London

Sound Insulation Testing in London

Unless plans were fully approved prior to 1 July 2003, sound insulation testing will be required on your London development between rooms or spaces that share a common area of separating wall and/or floor as stipulated in Building Regulations Part E for the passage of sound. Sound insulation Testing is not generally required for internal walls and floors within a dwelling-house, flat or room for residential purposes; however all internal partitions should be designed to achieve 40dB.

The buildings that 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.

The main aim of Sound testing in London is to ensure that minimum standards of sound resistance have not been compromised by poor workmanship and/or poor design. You are normally required to undertake sound testing to each type of construction, i.e. if you have a mixture of brick, blockwork, timber and metal studwork walls all four types would need to be tested, followed by a 10% sample of that type using the equipment shown in Plate A below.

Plate A – Our Sound Test Equipment.

sound testing equipment

For instance, if you have a project with 25 flats you would be required to do 3 x 6 pack of tests; each 6 pack contains 2 airborne wall, 2 airborne floor and 2 impact sound tests; however if any test failures occur, then the number of sound tests may need to increase on the development. When sound test failures occur, then the design and construction of the failed partitions will need to be revisited to try and evaluate the reasons for the failure; thereafter, agreement can be reached on how to rectify problem.

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 testing providing a ‘one stop’ solution for all your acoustic requirements.

If you would like more information in regards to sound insulation 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

Noise Damping to Improve Sound Testing

Noise Damping to Improve Sound Testing 

Noise damping is the most efficient and effective ways to control vibration and noise radiation at the source. Damping materials lessen this noise by turning the vibration into a low-grade heat. By using viscoelastic materials, it changes the resonant frequency of a substrate. By combining vibration damping materials and sound absorbers a composite acoustic construction can be achieved, that can control both airborne and structure borne noise – the final element for good soundproofing.

acoustic_wall_upgrade

It is worth noting that a  large number of manufacturers now produce a wide range of systems designed to improve sound insulation in homes and commercial buildings. In all instances, the effectiveness of these materials will vary depending on the situation in which they are installed. When choosing the acoustic product/s, detailed information on the likely sound insulation performance should be requested from the supplier. If you have an existing property you should check the existing construction of the dividing wall/floor partitions and work back from there. You are advised to give careful consideration to the data supplied by a manufacturer before using a proprietary product. it is also worth noting that the sound insulation value/s given for each product will be ‘best case’ as they have been tested in laboratory conditions and not on site – this is usually worse result by up to 3-5 dB) which may be the difference between a sound test pass or failure.

acoustic_floor_roll_

Also when undertaking remedial work to improve the sound insulation, the acoustic materials are often quite heavy which may result in considerable weight being added to the structure of a property. Thus it is essential to check that the ceiling or floor joists can carry the increased loads satisfactorily.

So in a nutshell if you allow for the following four main elements of sound insulation on your acoustic partition design; Decoupling, Absorption, Mass and Damping, your development should pass the sound insulation test at the first attempt.

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.

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.

Noise Problems in Refurbished Industrial Buildings

Noise Problems in Refurbished Industrial Buildings

We often get asked to undertake a series of sound test measurements to establish the acoustic performance of the wall of floors construction in existing buildings where the dwelling owners are concerned about excess noise.

In recent years the refurbishment of old industrial buildings into residential dwellings has become a very popular. Frequently the existing finishes of existing concrete, brick or wood Noise Problems in Refurbished Industrial Buildingsare left as the interior finish, supposedly to provide the “loft” type of décor. Such designs require even more acoustic design attention if sound privacy is to be achieved. Potential noise problems in refurbished industrial buildings can be quite challenging so buyers should insist that actual on-site sound insulation testing is undertaken to check the building has complied with the sound design performance criteria of Building Regulations Part E.

sound_transmission_through_floors

If you think you have a sound problem in your dwelling and are seeking help to resolve the problem, be sure to contact us and describe the problem in as much detail as possible. Describe the nature of the sounds, when and where you can hear it. Is it impact noise or airborne noise or a combination of both? If the unit is of recent construction you may need to procure a set of architectural drawings and mark-up which partitions noisiest. The more information you can provide us, the quicker we can try to determine the nature of the problem and subsequently find an acoustic solution for the partition/s.

We can also visit site and undertake sample testing on the dividing partitions. If the partitions fail the tests we can identify the main reasons for the sound test failures so targeted remedial treatments can be undertaken.

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 me directly 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.

Ceiling and Wall Assemblies for Part E

Ceiling and Wall Assemblies for Part E 

In our experience ceiling and wall assemblies, can be the main pathways for the two main types of sound transmission. The first type is the airborne sound –  such as loud music) and the second is impact sound, such as footfalls on the floor above.

If the ceiling and wall assemblies have been designed and constructed to provide adequate airborne isolation, impact noise can still be a problem. If the finished floor surface has been designed to accommodate carpeting, the carpeting and under pad will normally provide a good degree of impact sound isolation. On the other hand, if the finished floor is floor is constructed in hardwood, stone or ceramic tile. Achieving good impact sound isolation requires much more attention at the design stage to prevent potential sound test failures.

sound_transmission_through_floors

One of the main misconceptions is sound simply passes through materials, this is not the case. Sound waves are form of energy that energises any material that the sound waves come in contact with. Thus sound energy that impacts on a wall for floor/ceiling assembly will cause the material to vibrate like a radio speaker; the energised material then becomes the transmitter of the sound energy.

Thinner, more lightweight building materials often hold the key to effective noise control, by using materials with different acoustical characteristics that will dissipate and diffuse the sound energy. Insulation in the cavity converts some of the energy in to heat while a resilient channel will help minimise the direct connection of the gypsum board from one side of the assembly to the other. Each material and its relationship to one another, produces small increases in sound isolation that in turn reduces the transmission of sound through the whole system and subsequently improves the sound insulation characteristics of the acoustic partitions.

I hope the above article helps to explain the importance material selection within acoustic design.  If you would like more information or some acoustic design advice on your project, please don’t hesitate to contact me on info@aptsoundtesting.net or call me on 07775623464.

Reducing Noise in Residential Buildings

Reducing Noise in Residential Buildings

We often get asked how noise can be reduced in residential buildings such as apartments or terrace houses. One of the most common problems is noise transmission through the floor and ceiling assemblies in flats and through the wall partitions in houses. The usual noise problems range from airborne noise transmission from voices TVs and music to footfall impact noise caused by high heels on wooden/tiled floors.

Noise_Problems_Failed_Sound_Testing

In most cases for newer residential units many of the problems could have been prevented in the first place, if more attention had been paid to noise control during the design and construction process.   If the acoustic design has not been taken into account from the off-set of the project, then it becomes far more problematic and costly if noise problems are discovered and the partitions fail the sound insulation testing during the per-completion testing.

If you are contemplating the purchase of a unit, do not be afraid to question the contractor and the real estate agents about the sound insulation results for the unit. Ask if any of the units failed during the precompletion testing. In some cases just because a sample of the units had been tested during prior to handover doesn’t mean unit has been sound tested.

If you are not happy with the sound insulation properties of your unit then you may have a case to demand corrective action at the expense of others. If you have a noise problem that is not resolved and you go to sell your unit, you may be compelled to reveal the deficiency to a prospective buyer which may have an impact on the selling price.

If you need acoustic advice on your project, please don’t hesitate to contact us no at: info@aptsoundtesting.co.uk or call me direct on 07775623464.