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).

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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.

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.

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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.

Our Sound Testing Procedure

Our Sound Testing Procedure

Our sound testing procedure is quite simple and our acoustic 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.

sound testing equipment

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 insulation testing for more information.

The airborne and impact sound insulation tests carried out 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. 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.

If you would like advice on your acoustic design or sound testing in London, please contact us now at info@aptsoundtesting.co.uk or call us on 07775623464

SOUND TESTING FOR LONDON

SOUND TESTING FOR LONDON

London is a massive city containing in excess of 5 million dwellings, many sharing wall and floor partitions. In this noisy environment it is essential that good acoustic design and construction is incorporated into all new and refurbishment projects along with sound testing for London.

To try and help enforce good acoustic design principles, pre-completion sound testing was introduced in July 2003 to comply with new Approved Document E. The new building regulations required 10% of each party wall/floor construction type to be sound tested on all new build and conversion properties.

We have undertaken thousands of sound tests on converted properties in London and in our experience if the partitions haven’t received any acoustic upgrades the wall and floor partitions – as per the plate below) normally achieve approx. 30-35dB for airborne sound and 68-74dB for Impact Sound. Obviously these figures fall well short of the required 43dB & 64dB as stipulated in Approved Document E. Also, it’s worth taking into account that sound doubles every 10dB, so 30-35dB for airborne sound and 68-74dB for impact sound would be massive failures and careful acoustic design and construction upgrades would be required.

Detail 1: Existing Floor Partitions (rated at approx. 30-35dB)

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Using our many years’ experience in building acoustics, we are able to offer a total design and testing solutions for new and conversion projects. We help many architects and top 10 construction companies with their acoustic design requirements from the largest developments containing hundreds of units through a pair of semi-detached dwellings. We always endeavour to find the best solution, always taking build-ability and cost into consideration.

If it’s a conversion project and you are unsure of the floor/wall construction, we often recommend our ‘sample sound testing service. Firstly, we visit site and undertake sample sound testing to at least one floor and wall partition, is consists of at least one airborne and impact test to the proposed dividing floor and an airborne test to the dividing wall. Once the sound test results are established we can then offer a targeted acoustic design solution to achieve a successful sound test in London in compliance with Approve Document E.

Whatever the problem we can usually find an acoustic solution that will help you achieve Building Regulation compliance  If you have a project that’s needs acoustic design advice or needs sound insulation testing then please contact us at: info@aptsoundtesting.co.uk

Preparing Your Project For Sound Testing

Preparing Your Project For Sound Testing

There are many important things to remember as you near completion on your project, one of which is to adequately prepare your London project for Sound Testing. This means that the dwellings and the ‘habitable rooms’ i.e. living rooms and bedrooms should be the final finishing stage – usually a week or two prior to completion.

Sound_Insulation_Test_London

To help our clients prepare for compliance with Approved Document Part E throughout London, we have provided a site preparation checklist – shown below. It’s worth noting that where items are not in place this will negatively affect the sound insulation performance of the dwellings:

  1. Internal & external doors and windows must be hung, glazed & close-able on the latch.
  2. Trickle vents and other ventilation systems should be fitted and closed.
  3. All wall, floors & ceiling constructions must be completed
  4. Skirting boards and cornice should all be completed
  5. Electrical sockets, TV Aerial sockets & light switches should be fitted
  6. Rooms must be clear of building materials, tools & unfurnished
  7. No cosmetic floor coverings should be fitted (i.e. laminate, carpet, vinyl, ceramics)
  8. No noisy operations such as drilling, cutting or ground-works to occur nearby during testing
  9. Provision of 240v 50Hz mains power is required within all the dwellings under test 110v cannot be used.

To attain compliance with Approved Document E one set of tests needs to be undertaken for every ten flats or houses provided the construction system is the same. A set means that the test should include two locations where the party element (wall or floor) is tested. This is equivalent to two individual tests when assessing the performance of a wall – airborne performance only) and four individual tests when assessing a floor (two airborne and two impact tests).

All sound insulation tests must be undertaken between habitable spaces (e.g. bedrooms, living rooms) and not to or from common spaces such as stairwells and corridors. Approved Document E 2003 states that a minimum of 10% of all party walls and floors is sound tested for every construction group or sub-group; however, where variations in the construction such as a different wall and/or floor type then further testing may be required.

APT Sound Testing provides a full range of Sound Testing in London in compliance with Approved Document E. if you would like more information please contact us at info@aptsoundtesting.co.uk or call me direct on 07775623464.

Sound Testing on Conversion Projects

Sound Testing on Conversion Projects

In our experience acoustic design and sound testing on conversion projects don’t need to be problematic. If you are currently in the process converting offices and/or houses info flats or ‘Rooms for Residential Use’, then its very important that the acoustic design is embraced from the start of the project.

Air Pressure Testing  have many years of experience in providing acoustic design and sound insulation testing in a comprehensive package designed to help you meet the legal requirements of Building Regulations Part E.

Acoustic Design Advice

As a  multi UKAS accredited company, you can be sure that all our services are undertaken to the highest laboratory standards. The types of projects that need to comply with Approved Document E for conversion projects or ‘Rooms for Residential Use’ are:

  1. House to flat conversions
  2. Commercial building to flat conversions.
  3. Hotels and hostels
  4. Boarding houses
  5. Halls of residence
  6. Residential homes

We can offer you the following services to help your development comply with Approved Document E:

  1. We review the architect’s drawings to check the required acoustic principles have been followed and meet the requirements of Approved Document E.
  2. We undertake a site visit and analyse the current state of building construction. And to check there are no site specific construction problems that may affect the acoustic performance of the building.
  3. We under take sample sound testing to check the sound insulation properties of the buildings existing floors and walls.
  4. We will provide you with a full and detailed acoustic design report that outlines which acoustic treatments taking into account the most cost and buildability.
  5. We will provide ongoing support and site visits to assist the builder/consultant to ensuring that the level of detail required is met and deal with any ongoing issues that may arise.
  6. We will undertake the final precompletion sound testing to achieve compliance with Approved Document E.

We’ve successfully guided our clients through hundreds of different conversion projects helping our clients achieve compliance with Approved Document E.

If you would like advice on your acoustic design or sound testing in London, please contact us now at info@aptsoundtesting.co.uk or call us on 07775623464.

Airborne and Impact Sound Tests

Airborne and Impact Sound Tests

You are required to undertake two types of sound testing to comply with Building Regulations Part E, they are Airborne and Impact sound tests. Airborne sound tests are undertake on wall and floors and impact tests are undertaken on floor only.

To test the sound insulation properties of a floor or wall via airborne sound testing, you need to provide a sound source which consists of an amplifier and loud speaker is set up on one side of the wall or floor partition that is to be tested. We then turn the setting to turn on Pink noise. Pink noise sounds like the static that can be heard on a radio that is off station. Pink noise is used  because it is made up of a wall of sound that has a wide spectrum of frequencies. This provides an indication of sound insulation performance for a wide range of sounds that may be experienced within a dwelling from musical instruments to loud TV noise sources.

sound testing

The pink noise is measured in the room which contains the speaker or sound source using a Class 1 Norsonic sound level meter; thereafter the noise is measured on the other side of the wall or floor partition that is being tested. In layman’s terms the difference between these two levels is the amount of sound that is stopped by the sound insulating qualities if the wall or floor partition/s. The result is then corrected and adjusted depending on the echo or reverberation time within the receiving room, and any background noise such as builders work noise etc.

To test the impact sound insulation performance of a floor, a Norsonic tapping machine which consists of five small hammers that are dropped onto the floor to simulate foot fall, is placed on the floor. The resultant noise in the room below is measured with a Norsonic Class 1 sound level meter and the amount of noise that passes through the floor is the impact sound transmission level and is expressed as a single number. This result is then corrected and adjusted depending on the reverberation time of the rooms as well as any background noise to give the impact sound transmission result (LnT,w).

Impact Sound Testing

Both types of sound tests results are then compared to the performance criteria of Approved Document E, which stipulates that airborne sound needs to achieve 45dB for new build & 43dB for conversion projects. To achieve a pass for impact sound testing you need to achieve 62dB for new build & 64dB conversions.

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

Sound Testing Services for New Dwellings

Sound Testing Services  for new dwellings

Sound Testing Services became mandatory in England & Wales in 2003, when Approved Document E was updated. Approved Document E requires new and converted to achieve a reasonable level of sound insulation between dwellings. The easiest way simplest way to comply with the requirements of Approved Document E; is to have on-site pre-completion sound insulation testing carried out on your project.

Many of our clients are clients are apprehensive prior to having to undertake pre-completion sound insulation tests.  This is often down to the fear of failure; however if the the acoustic design specification has been undertaken from the offset of the project and is closely followed during the construction phase then he chance of potential failure is greatly reduced.

sound testing equipment

Approved Document E requires a minimum of one ‘set’ of tests for every ten units in each group and/or sub group.  This is usually broken down to two airborne wall, two airborne floor and two impact sound tests. If you have a development of 25 houses, with five different sub-groups (5 units in each) then you would usually conduct 5 ‘sets’ of tests.  If no separating floors are available, i.e. in semi-detached or terraced houses, one set of tests would consist of two airborne tests of separating walls only.

If the precompletion test results do not satisfy the performance criteria of Approved Document E, then our test engineer will attempt to determine the possible causes of failure. This may be to do with construction detailing around services or at junctions, or simply, poor acoustic design. Once a specific reason for failure has been determined, we can then advise the client on remedial actions that can be undertaken.

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

Successful Sound Testing in London

Successful Sound Testing in London 

From the offset careful consideration should be shown to the acoustic design detailing for both conversion and new build projects if you are to achieve a successful sound testing in London at the first attempt.

For instance many of the dwellings in London consist of flats converted from large Victorian houses. At the time of the original build some 100 years ago, designing for sound insulation was not a consideration and so many of the dwellings suffer from adverse noise transference between the floor and wall partitions. This can be extremely stressful to the occupant’s well-being is a major cause for concern.

ACOUSTIC_DESIGN

There are ways to improve the airborne and impact performance by improving the wall/floor partitions ability to reduce the amount of sound transmission from one side of a construction element to the other and subsequently  from dwelling to dwelling. By adding isolation and  mass to the floors and wall construction compliance with Part E for conversion projects can be achieved.

To help our clients achieve successful sound testing we offer the following ‘3 step package’:

  1. Sample Sound Testing of the existing building. 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.
  2. Acoustic Design Review of the proposed developments party walls and floors to ensure acoustic details with be sufficient to pass Building Regulations Part E
  3. Site Survey Visits to check that the onsite construction is being undertaken in-line with manufacturer’s guidelines.

In our experience 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.  In many cases sound test failure is down to poor acoustic design and poor workmanship, that is why we offer the 3 step process to achieve successful sound testing on your London project.

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.

Sound Testing Terminology (2 of 3)

Sound Testing Terminology (2 of 3)

Often confusion can arise from the large amount of ‘terms’ used in conjunction with acoustic design and sound insulation testing. To help with this we have made a list of the following terms for clarity – this is the second of three blogs:

Façade Testing  – This Standard – ISO 140-5:1998) specifies the testing methods to evaluate the sound insulation in buildings and building elements for facades. Three rounds of a proficiency testing scheme for airborne sound insulation measurements have been performed according to the methods specified in the standard for a whole facade by using an external loudspeaker as the noise source.

sound testing equipment

Flanking element (flanking wall) – This is any building element that contributes to the airborne sound or impact transmission between rooms in a building which is not the direct separating element (i.e. not the separating wall or separating floor).

Flanking strip or edge strip – This is a resilient strip using foamed polyethylene normally 5 mm thick, which is located at the perimeter of a floor to isolate the floor boards from the walls and skirting.

Flanking transmission  – This is airborne or impact transmission between rooms that is transmitted via flanking elements and/or flanking elements in conjunction with the main separating elements. An example of a flanking element is the inner leaf of an external wall that connects to the separating ‘core’ of a wall or floor.

Flexible closer – This is a flexible cavity stop or cavity barrier which seals the air path in cavities linking adjoining dwellings.

Floating floor treatment (FFT) – This is a timber floating floor system which may use battens, cradles or platform base, all of which use a resilient layer to provide isolation from the base floor and adjacent wall elements.

Gypsum based plasterboard  – This is a dry lining board applied to walls, ceilings and within floating floor treatments which has gypsum content. It may also have fibre reinforcement within the board.

Impact sound – This is sound which is propagated from a noise source through a direct medium. An example of this is footfall on a floor.

Impact sound transmission – This is sound which is spread from an impact noise source in direct contact with a building element.

We hope the above information in regards to Sound Testing Terminology has been helpful. If you would like more information in regards to acoustic design and sound testing services, please contact us at info@aptsoundtesting.co.uk or visit our website at: www.aptsoundtesting.co.uk