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.

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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.

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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.

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.

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.

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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.

 

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.

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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.

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.

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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.

The Two Types of Floor Noise

The Two Types of Floor Noise

Under Building Regulations Part E there are two distinct types of floor noise to consider; they are:

  • Airborne Noise (for example speech and music)
  • Impact Noise (for example footsteps directly on the floor above)

By utilising our extensive knowledge of different materials and construction Even if both types of sound appear to be are excessive through the ceiling/floor, then there are some easy acoustic design upgrades that should reduce the sound levels and improve your sound test results. By utilising our extensive knowledge of different materials and construction we can forward a simple, cost effective solution for wall and/or floor upgrade. Where our clients have followed our advice they have achieved a 100% success rate for sound insulation testing – ensuring compliance with Part E of Building Regulations.

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The 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

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. 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.

We can carry out final pre-completion sound testing on all new build or conversion projects throughout London. If you would like advice on your acoustic design or sound testing please contact us now at info@aptsoundtesting.co.uk or call me now 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

GOOD ACOUSTIC DESIGN AND CONSTRUCTION

GOOD ACOUSTIC DESIGN AND CONSTRUCTION

Unfortunately there are many misconceptions when it comes to acoustic design and construction. Unfortunately by simply constructing a good separating wall or floor this may not in itself provide sufficient sound insulation to pass the sound testing for Part E as the junctions of each separating wall and/or floor with other parts of the building are equally as important. There may be other potential issues such as flanking sound transmission that can occur via construction components such as:

  1. the internal partitions
  2. the inner leaf of the external wall
  3. the external wall cavities
  4. the external façade or outer leaf
  5. the roof structure
  6. the foundations.

The overall design and construction system should therefore be considered and not just the separating wall or floor partitions.  Flanking sound 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 where there are large existing penetrations through the floors.

NoiseFlankingWall

Also, it is never safe to assume because the architect has specified high performance walls, windows and floor/ceiling assemblies that the materials and onsite workmanship will result in compliance with the anticipated results. You should usually reduce the acoustic target by 4-5dB due to onsite construction. When the construction assembly is tested in the lab, it is also certified and the installation techniques are described and undertaken in great detail.  Unfortunately it is not always possible to replicate the exact conditions on the site compared to the ideal conditions within in a lab setting, which is a far more controlled and scrutinised environment. This is the reason why a 5 point difference is allowed between the construction design on paper and the actual on site sound insulation performance.

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 have the technical experience to help identify and rectify your soundproofing or noise control problem.

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 or visit our website at: www.aptsoundtesting.co.uk

The different types of Sound Testing

The different types of Sound Testing.

There are two distinct types of noise to consider through floors, they are:

  • Airborne Noise (for example speech and music) and
  • Impact Noise (for example footsteps directly on the floor above)

To take this into account there are two different types of Sound Testing required in compliance with Approved Document Part E. Even if both types of sound are emitting through the ceiling/floor then there are some easy installations that should reduce the sound levels and improve your sound test results.

sound testing equipment

To help our clients overcome this problem, we also offer our acoustic design service which helps clients to pass the sound testing upon completion of the acoustic upgrade. By advising on a simple cost effective wall and/or floor upgrade, we are able to forward simple to follow acoustic design reviews, utilising our extensive knowledge of different materials and construction methods. Using this philosophy, to date, we have had no sound test failures where our acoustic upgrades have been incorporated into the site construction, ensuring compliance with Part E of Building Regulations.

Pre-completion sound testing has been a mandatory requirement since July 2003 and all new build properties and conversions which were built after this date require 10% of each party wall/floor construction type to be tested. The Sound testing is to be carried out between pairs of rooms separated by party walls and/or floors. Part E stipulates that it sound testing should take place between dividing partitions between living rooms and bedrooms as these are classed as the two main habitable rooms; however, other rooms can be used if this is not possible such as dining rooms, kitchen and studies.

APT Sound Testing can undertake UKAS accredited Part E sound testing throughout England and Wales. Our sound test engineers carry all the latest class 1 acoustic equipment and we provide full UKAS accredited air and sound testing, so our clients can be sure that all testing is completed to the strictest  ISO quality controlled standards.

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

Simple Design Solutions to Pass Part E Sound Testing

Simple Design Solutions to Pass Part E Sound Testing

There are many simple solutions to reduce the noise levels and achieve compliance with Part E sound testing. We can provide easy to follow acoustic design reviews, utilising our extensive knowledge of different materials and construction methods.

Our clients often convert large houses into multiple flats, i.e. a flat on each of the ground, 1st and 2nd floors. They usually leave the floor boards in place and install a layer of plasterboard to the underside of the existing plasterboard/lathe and plaster. Unfortunately this simple type of upgrade usually achieves 30dB for airborne sound, which will result in sound testing failure. The sound test result needs to be 43db and above for airborne noise and 70dB for Impact sound.

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One simple solution to overcome the above problem would be to add another ceiling element to the overall construction. This can be achieved by incorporating resilient metal bars which are connected to the underside of the joists and mounted perpendicular (90˚) to the joist direction. If plasterboard has already been tacked to the underside of the joists you can firstly add timber batten and then add the resilient bars, also mounted perpendicular (90˚ to the batten, thereafter 2 x 12.5mm layers of soundboard can be tacked to the underside of the resilient bar and an acoustic insulation added to the newly formed void. In between the joist void add 100mm acoustic insulation. Above the floor boards add an acoustic resilient membrane to lower the chance of impact noise transmitting down to dwelling below.

Acoustic_Ceiling_Upgrade

The aforementioned acoustic design solution will usually result in successful sound testing and compliance with Approved Document Part E.

If you require more information in regards to sound testing and/or acoustic design on your project please visit our site at www.aptsoundtesting.co.uk or contact us at info@aptsoundtesting.co.uk, or call me direct on 07775623464.