Acoustic Terminology M-S

Acoustic Terminology M-S

Our previous blog explained the  of acoustic terminology, this blog covers  M-S.

Mass

This is a physical quantity that expresses the amount of matter in a body. Walls and floors may be described in terms of the surface density (mass per unit area, kg/m2) of the wall face or the floor surface, which is the sum of the surface densities of each component of the construction. The density of materials is expressed as mass per unit volume, kg/m3, which can be provided via the core structure and linings such as in-situ concrete or solid dense block walls.

Mass per unit area (or surface density)

This is is expressed in terms of kilograms per square metre (kg/m2). This is often used to describe boards, panels, flooring and dry linings (see gypsum based board).

Resilience

This can reduce structural vibration transmission and still maintain material performance and overall dimensions, examples include floating floor treatments such as resilient battens or cradles, or resilient ceiling bars.

Resilient ceiling bars

This acoustic solution is generally metal based and vary in thickness from 11 mm to 30 mm. They are mounted perpendicular to the joist span direction and can increase both airborne and impact sound insulation. Care should be taken to ensure that the ceiling board fixings into the resilient bar do not come into contact with the joists and reduce the potential performance.

Resilient noggin

This is a small section of resilient ceiling bar which is used to assist in bracing non load bearing partitions.

Rw

This is a single-number quantity (weighted) which characterises the airborne sound insulation of a building element from measurements undertaken in a laboratory, in accordance with BS EN ISO 717-1: 1997

Sound Insulation Testing

Sound Insulation Testing is required near the end of a development to show that the performance of the party wall and floor partitions meet the standards as stipulated in Building Regulations Approved Document E. The testing methods for airborne and impact sound insulation is in full accordance with the suggested methods presented in BS EN ISO 140-parts 4 & 7: 1998.

Stiffness

This is can improve low frequency sound insulation, for example in floors, by reducing the potential for deflection or movement of the primary structure, therefore the correct spacing and depth of joists is important.

If your project requires some acoustic design input and/or sound insulation testing please don’t hesitate to contact us at info@aptsoundtesting.co.uk or call Darren direct on 07775623464 or visit our website at: www.aptsoundtesting.co.uk

Acoustic Terminology C-F

Acoustic Terminology C-F 

Our previous blog explained the A-B of acoustic terminology, this blog covers C-F.

Cavity stop

This is a proprietary product or material such as mineral wool (fibre) used to close the gap in a cavity wall.

Composite Resilient Batten

This is composed of a timber batten with a pre-bonded resilient material to provide isolation between the flooring surface layers and floor base.

Cradle/Saddle

This is an intermediate support system (with a resilient layer base, either pre-bonded or already integral) using levelling packer pieces to support a timber batten, isolating it from the floor base.

Decibel (dB)

This is the unit used for different acoustic quantities to indicate the level with

respect to a reference level.

Density (kg/m3)

This is the mass per unit volume, expressed in kilograms per cubic metre (kg/m3). Blockwork is commonly referred to by industry in terms of strength (in Newtons). However, it is the density that has the important role in terms of sound insulation.

Direct transmission refers to the path of either airborne or impact sound through elements of construction.

DnT,w

This is the weighted standardized level difference. A single-number quantity (weighted) which characterises the airborne sound insulation between two rooms, in accordance with BS EN ISO 717-1:1997

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.

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).

Room-Integrity-Design

If you need acoustic design advice and/or sound insulation testing please let us know. APT Sound Testing will ensure you will have direct contact with the allocated acoustician from the start of the process, through to the successful completion of the sound insulation testing.

If you would like more information in regards to acoustic services, please contact us at info@aptsoundtesting.co.uk or visit our website at: www.aptsoundtesting.co.uk

Our Acoustic Services

Our Acoustic Services

APT Sound Testing offers a full turnkey solution for all your acoustic requirements to ensure compliance with Building Regulations Part E and achieve building control sign off for the acoustic elements of the project. This ensures your company receives professional advice every step of the way, with an on-going continual consideration of cost.

Our acoustic services consist of the following elements:

Sample Sound Insulation Testing

We visit site to undertake sample sound testing to the existing buildings walls and floors to check the sound insulation performance of the existing dividing partitions. Thereafter, once the sound levels have been established and targeted acoustic design can be undertaken to ensure compliance with Building Regulations Part E.

sound testing equipment

Acoustic Design Service

We can help develop the acoustic design of the project from the initial design scheme stage through to the precompletion sound testing. In particular we review the acoustic details to take into account the mass, isolation and absorption elements of the construction.

Site Survey Visits

We offer site survey visits which allow you (the client) and your contractor to feel confident about the outcome of testing at the end of the build. The site visits let us check that the installation teams are installing the acoustic materials as per manufacturers avoiding crucial onsite mistakes. You can often have a compliant design which still fails due to poor workmanship; the site survey visits negate the risk of sound test failure.

Acoustic_Site_Survey

Sound Test Failures

If your building fails the sound testing, we can use our experience in building construction and acoustics to firstly diagnose the reasons for the sound test failure and thereafter recommend a cost-effective solution to allow you to achieve building regulation compliance.

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.

Acoustic Design Service

Acoustic Design Service

The importance of good acoustic design and construction should not be under estimated. If a project fails its precompletion sound testing it may need costly remedial works to comply with Building Regulations Part E.

On new build developments we offer comprehensive acoustic design via coordination with the lead consultant. We can also visit site during the construction process to undertake a detailed site survey visit to check the onsite construction is as per the construction details – this is often good to ensure the relevant parties are fully aware of the installation detail required, which in turn may highlight possible ‘onsite’ construction problems.

Acoustic Design Service in London 

Acoustic_Site_Survey

On conversion projects we can visit site and undertake sample sound testing, this will evaluate the performance of the existing floor and wall partitions, which allows for targeted acoustic design as the acoustic performance of the dividing partitions may be already good –  especially if the buildings floors are constructed out of cast in situ concrete.

APT Sound Testing  provides a consultancy design service to Architects, Property Developers and Building Contractors. We specialise in helping small developers pass their sound testing to achieve Part E compliance for all types of project such as new build properties, blocks of flats and conversions.

Sound_Testing_Flats

Many of our clients have previously conveyed negative feedback that larger acoustic consultancies don’t understand small builder requirements and subsequently often produce complicated acoustic design detailing that are both difficult (in terms of build-ability) and very costly to undertake. We try to provide acoustic solutions that are cost effective and easy to construct, saving our clients time and money.

If you would like more information in regards to our acoustic design service and/or 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

 

Noise Complaints in Existing Apartment Blocks

Noise Complaints in Existing Apartment Blocks

Over the last few years we are noticing a rise in noise complaints in existing apartment blocks. There may be many reasons for this. Noise problems range from airborne noise transmission from voices TVs and music to footfall impact noise caused by high heels on wooden/tiled floors – it is usually the impact noise that is noticed most by the residents if the unit above has changed their floor finish from carpet to wood.

Excessive-Noise

In many cases even if the floor assembly has been designed and constructed to provide adequate airborne isolation, impact noise can still be a major problem. One of the main problems is if works to the floor finish have been undertaken, changing it from carpet to timber. Even if it passes the sound test, the perceivable rise in impact noise often leads to complaints, as carpet and underlay normally provides a good degree of impact sound isolation. Taking this into account it’s very important that impact isolation design, is taken into account before the installation of a hardwood and/or ceramic tile finish.

If you think you may have a problem with sound in your dwelling and/or you have encountered complaints from a neighbour due to changes you have made to the floor finish then please contact us now. Try to describe the noise problem in as much detail as possible. Describe the nature of the sounds, when and where you or your neighbour can hear it. Is it impact noise or airborne noise or a combination of both? The more information you can provide us, the quicker we can try to determine the nature of the problem and find a solution. It may be as simple as the installation of an acoustic resilient membrane to the floor.

Acoustic_Site_Survey

In our experience, if careful consideration is shown to the acoustic element of the floor upgrade, it should reduce the chance of complaints at a later stage, which will also avert costly legal battles at the end of the project and which often leads on to expensive remedial works.

We can come in prior to works commence and undertake a sample sound test of the existing floor partition, thereafter we can advise on the acoustic design of the floor. once the works have been completed we can then undertake a final precompletion sound test to show compliance with Building Regulations Part E.

If you are about to make changes to your apartment floor, and you require acoustic design advice, then please contact us now at: info@aptsoundtesting.co.uk  or phone me directly on 07775623464.

Sound Testing for Approved Document E

Sound Testing for Approved Document E

Approved Document E – ‘Resistance to the passage of sound’ became part of the building regulations on July 1st 2003 and provides minimum sound insulation Building Regulation requirement for new build and conversion dwellings. Properties include houses, flats, hotels, student residences, care homes are all now required to be sound tested under approved document E.

Part E Sound Testing

Part-E-Sound-Testing

Approved Document E is a government issued document providing guidance for developers, architects and building control bodies as well as other bodies involved in the design and conversion of buildings for residential purpose. The document explains the testing requirement for each type of project and provides some good advice and details about building procedures and materials that affect test results.

In Part E it defines the two types of sound – ‘airborne sound, which is sound generated and transferred directly in the air by talking or home entertainment systems such as music systems or Televisions) or ‘impact sound, such as sound generated by the impact of an object striking the floor and transmitted through it, such as footfall noise).

Excessive Noise Problems

Excessive-Noise

The objective of Approved Document E is to raise sound resistance standards and reduce excess noise for tenants for both airborne and impact noise, which in turn will to provide reasonable living conditions and improve the well-being of tenants. Sound insulation testing may also be required in non-residential buildings such as schools, hospitals and workplaces to ensure that noise sensitive areas such as classrooms, wards and meeting rooms are suitably insulated from noisier areas, notably BREEAM projects usually require sound insulation testing. In rare cases the sound testing of external facades may also be  a requirement.

APT Sound Testing are a UKAS and ISO accredited company.

If you would like more information in regards to our sound testing services please contact us at: info@aptsoundtesting.co.uk or visit our website at: www.aptsoundtesting.co.uk

The Different Types of Sound Insulation Testing

The Different Types of Sound Insulation Testing

Sound Testing has been mandatory requirement since July 2003. All new build dwellings and conversions which were built after this date require 10% of each party wall/floor construction type to be tested.

Sound Insulation Tests needs to be carried out between pairs of rooms separated by party walls or floors, i.e. in block of flats you would undertake airborne testing across the walls and floors; and impact tests across the floors.

Sound_Testing_Flats

You usually try to undertake testing between the two main habitable rooms, such as living rooms and bedrooms. The sound test procedure involves setting up a noise source in a room on one side of the party wall or floor and measuring the noise on both sides of the partition with a class 1 analyser.

Airborne Sound Insulation Tests

Airborne sound insulation tests may be required between horizontally and vertically separated pairs of rooms. The sound tests are undertaken by using a sound source, amplifier and loudspeaker to generate a high noise level in one room (the source room). Noise measurements are then taken in both the source and receiver rooms using a prescribed number of source and microphone positions.

Sample_Sound__Testing

The background levels in the receiver room are measured and the reverberation time in the receiver room is also measured. From the results, the airborne sound insulation (DnT,w + Ctr) is calculated and compared to the requirements of Approved Document E.

Impact Sound Insulation Tests

For vertically separated rooms Impact sound Insulation testing may also be required. This sound test is undertaken using a “tapping machine”, (as above) which drops a series of weights onto the floor of the upper room. The noise level in the lower (receiver) room is measured for a prescribed number of source and microphone locations. The background levels in the receiver room are measured and the reverberation time in the receiver room is also measured. From the results, the impact sound insulation (L’nT,w) is calculated and compared to the requirements of Approved Document E.

Impact Sound Testing

We use the latest Norsonic equipment, which is class one rating and UKAS calibrated. We are a UKAS and ISO accredited company, so you can be assured all our testing is carried out to the strictest quality controlled standards.

If you would like more information in regards to sound testing please follow our blog at: http://soundtestinguk.blogspot.co.uk/, or contact me (Darren) on 07775 623464 ot email us at info@aptsoundtesting.co.uk

Excessive Noise Flanking can lead to Sound Test Failure

Excessive Noise Flanking can lead to Sound Test Failure

Noise Flanking is a term used by acoustic engineers to describe where passes sound over the top or under the primary partition separating the two spaces under test. Noise flanking usually appears due to insufficient isolation of materials thus allowing sound to travel through the partition. Unfortunately excessive noise flanking can lead to a sound test failure.

Noise_flanking

One way to reduce the chance of noise flanking transmission is through a careful consideration to the acoustic design from the start of the project.  Unfortunately, by simply specifying high performance wall and floor partitions it is no guarantee to adequate sound isolation and successful sound testing, extra care must be shown to the mass, isolation and absorption values of the acoustic construction.

APT Sound Testing offer both preconstruction and post construction ‘remedial’ design solutions to achieve a successful sound insulation testing in-line with Part E of Building Regulations. We also offer onsite inspection services to ensure that the sound insulation elements are being installed as per manufactures guild-lines.

Acoustic_Design_Service

Also, in our experience 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 at least 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 in detail and the construction is undertaken within Laboratory conditions, which is a far more controlled and scrutinised environment. Unfortunately, it is not always possible to replicate Laboratory conditions on site due to its more chaotic nature with multiple trades working next to each other. This is the reason why a 5 point difference is allowed between the construction design on paper and the actual on site sound testing performance.

We have undertaken hundreds of acoustic design reviews on all types of projects to help our client achieve compliance with Building regulations Part E, we provide a ‘one stop’ solution for all your acoustic requirements.

If you would like more information in regards to our acoustic design service and/or sound testing service, please follow our blog at: http://soundtestinguk.blogspot.co.uk or contact us at: info@aptsoundtesting.co.uk or call me ‘Darren’ direct on 07775623464.

 

Why have I failed my Precompletion Sound Testing

Why have I failed my Precompletion Sound Testing?

There are many reasons why dwellings fail precompletion sound testing. 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.

Sound_Insulation_Testing_Equipment

The most common noise flanking pathways are as follows:

  1. Ceiling Partitions – Above and Through the Ceiling Space (where an adequate acoustic break has not been integrated within the ceiling void)
  2. Floor Partitions – Through Floor and Floor Joist Space (if insulation has not been installed or direct fixing to joists without a drop ceiling below the partition under test)
  3. Shared Structural Building Components – Floor Boards, Floor Joists, Continuous Drywall Partitions, Continuous Concrete Floors, and Cement Block Walls.
  4. Through Structural Steel (structural steel beams are often a major cause of noise transmission as plasterboard is often fixed directly to the steel without sound breaks)
  5. Plumbing Chases – Junctures Between the Walls & Floor Slab Above or at the Exterior Wall Juncture (this should be filed with mortar etc. to add mass to this weakened area)
  6. Through Windows (if they are no double glazed or have secondary glazing as a minimum)
  7. Fixtures & Outlets – Light Switches, Telephone Outlets, and Recessed Lighting Fixtures (if penetrations have been cut back to back with the opposite dwelling under test)
  8. Structural Joints – Perimeter Joints at Wall & Floor, Through Wall & Ceiling Junctures (these should be filled with acoustic mastic)
  9. Around the End of the Partition Through the Adjacent Wall (acoustic mastic should be used to seal this junction)

In many instances we have found that existing floor structures of a minimum of 200mm concrete usually achieve the airborne standard as stipulated by Building Regulations Part; however, the impact results are usually poor due to inadequate acoustic insolation between the floor constructions. This is because the airborne sound is easily broken down by the mass of the concrete slab, therefore sounds such as speech & TV etc. are minimised. Unfortunately, impact sound results are poor due to the lack of isolation within the slab, therefore the sound travels straight through the slab to the area below.

Sound_Insulation_Test_London

To help reduce potential control noise issues APT Sound Testing can undertake an acoustic design review of the floors after sample sound testing to ensure both the airborne and impact sound tests are allowed for during our acoustic design service.

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

 

Acoustic Design and Sound Testing

Acoustic Design and Sound Testing

We are currently experiencing a large rise in the amount of housing stock that’s requiring sound testing throughout the UK. As commercial buildings such as offices etc. are converted into residential dwellings sound testing then becomes are requirement under Part E of building regulations. We have carried out a large amount of sound testing in office conversions with varying success as office buildings are not usually designed with acoustics in-mind.

Noise_Problems_Failed_Sound_Testing

To reduce the chance of a sound test failure, it is imperative that flanking transmission is considered at the design stage and any construction detailing is specified to minimise any potential of noise flanking which will downgrade the acoustic performance. 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.

When offices are converted into dwellings we often undertake sample sound testing to check the existing sound levels prior to the commencement of works, once we have established the sound test results we can then come up with a more cost effective design to comply with Part E of Building Regulations.

Historically we have found that if the floor structure is a typical 200mm concrete slab the sample airborne results are coming close to the requirements of Part E without any modifications to the existing slab; however, the impact results are poor. This is because the airborne sound is broken down by the mass of the concrete slab, therefore sounds such as speech & TV etc. are minimised. Unfortunately, impact sound results are poor due to the lack of isolation within the slab, therefore the sound travels straight through the slab to the area below. Sound such as people walking can be very loud and unacceptable.

To help reduce potential control noise issues APT Sound Testing can undertake an acoustic  design review of the floors after sample sound testing to ensure both the airborne and impact sound tests pass Part E of Building Regulations. Using our extensive knowledge regarding the way different materials and construction methods can influence the results of sound testing we can offer easy to follow acoustic advice on the most awkward developments.

Acoustic_Design_Service

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