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

 

How are Plots Selected for Sound Testing?

How are plots selected for sound testing?

APT usually specifies the amount of sound insulation tests that are required. Firstly we look through the floor plans to work out a testing schedule taking into account the positioning of habitable rooms, the room and partitions sizes. We always tests through ‘habitable rooms’ partitions i.e. lounges & bedrooms wherever possible – as per the details shown below). We will also try and undertake testing across walls and floors in different areas of the building and through different partition types i.e. if one wall is made of masonry and the other met-sec partitioning.  Once we have specified the sound testing schedule, the client should show building control to seek their approval before the commencement of the sound testing.

Detail A – Sound Testing through Walls

Plan_Sound_Test_Through_Walls

Detail B – Sound Testing through Floors

Plan_Sound_Test_Through_Floor

What are the minimum requirements for separating party walls and floors?

The minimum requirements of ADE can depend on a variety of factors such as if the development is new build or refurbished, whether the development is intended to be a permanent dwelling, or classified as “rooms of residential purposes” (e.g. hotels, student accommodation, etc). A brief summary of the minimum requirements can be found below:

DWELLING HOUSES AND FLATS Airborne standard

DnTw,w+Ctr dB

Impact Standard

L’nT,w dB

 

Purpose built dwellings

Walls at least 45 N/A
Floors and Stairs at least 45 up to 62
 

Dwelling formed by material change of use

Walls at least 43 N/A
Floors and Stairs at least 43 up to 64

 

ROOMS FOR RESIDENTAIL PPOSES Airborne standard

DnTw,w+Ctr dB

Airborne standard

L’nT,w dB

 

Purpose-built rooms

Walls at least 43 N/A
Floors and Stairs at least 45 up to 62
 

Rooms formed by material change of use

Walls at least 43 N/A
Floor and Stairs at least 43 up to 64

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.

Noise Flanking Paths

Noise Flanking Paths

To reduce the chance of sound testing failure, it is imperative that flanking transmission is considered at the design stage to reduce potential noise flanking paths. 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.

sound_transmission_through_floors

Flanking sound is defined as sound from a source room that is not transmitted via the separating building element e.g. the wall or floor partition. The sound is transmitted indirectly via paths such as external walls, windows, doors and internal corridors. One of the easiest ways of dealing with sound flanking issues is to use isolation strips around the perimeter of the partitions at the edges of floors and walls, this should be finished with acoustic sealant

One of the main reasons for flanking sound test failures is when the inner leaf of the perimeter wall is built with light weight blocks. This acts like a large snare drum and the sound simple travels straight up the wall from one flat to the flat above and/or below. Even if you have used a acoustically robust wall and/or floor partition the sound insulation testing may still fail. If you have used lightweight blocks in your onsite construction and the building fails the sound test you may need to construction independent internal plasterboard lining throughout the inner perimeter wall, this should isolate the lightweight blocks and ensure the flanking path is minimized.

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.

If you would like more information in regards to sound insulation testing and or acoustic design advice, then please call us now at info@airpressuretesting.net or call me (Darren) direct on 07775623464.

Sound Testing Definitions and Terms (1 of 2)

Sound Testing Definitions and Terms (1 of 2) 

Sound testing is usually undertaken near the end of a project to show that the party wall and floor partitions meet the standards shown in Building Regulations Approved Document E.  The method for testing for airborne and impact sound insulation is in full accordance with: the suggested methods presented in BS EN ISO 140-parts 4 & 7: 1998. Sound tests are broken down into various rating methods. The sound insulation definition and terms are as follows:

What is Sound Insulation?

Sound is transmitted through most walls and floors by setting the entire structure into vibration. The higher the transmission loss of a wall, the better it functions as a barrier to the passage of unwanted noise. There are two types of sound insulation testing in buildings: airborne and impact.

Airborne Sound

This is sound caused by vibrations which transmit through a medium and reach the ear or some other form of detecting device. Sound is measured in loudness (decibels (dB)) and frequency (Hertz (Hz)). Airborne sound (or airborne noise) is sound that is transmitted through the air.

Noise_Problems_Failed_Sound_Testing

Impact sound

This is sound arising from the impact of an object on a building element – wall, floor, or ceiling. Typical sources are footsteps, jumping, and dropped objects. Impact sound transmission occurs because the impact causes both sides of the building element to vibrate, which generates sound waves.

Flanking Noise Transmission

Flanking is the transmission of sound from a source room to a receiving room by paths other than straight through the separating wall and/or floor partition. For example, impact sound may be transmitted from one room to another through a common timber floor. Other common mechanisms for flanking transmission include suspended ceilings, pipework, ducting, etc. Flanking sound is always present, except in the ‘ideal’ acoustics laboratory. In practice the sound insulation is often limited by the flanking transmission.

If you have a project that’s needs acoustic design advice or sound insulation testing, then please contact us at: info@aptsoundtesting.co.uk or phone me (Darren) directly on 07775623464.

 

Sound Test Procedure

Sound Test Procedure 

The Sound Testing procedure is fairly 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.

Sound_Insulation_Testing_Equipment

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.

Ongoing problems with airborne and structure borne sound are often associated with direct noise flanking transmission through floors and supporting walls and other associated structures. One common cause of noise flanking is often associated with the inclusion of lightweight blocks within the construction of the building envelope and/or blocked cavities. It all cases it is essential to establish if your problem is due to direct transmission, flanking transmission or a combination of both so that the most cost effective remedial treatment can be chosen.

We offer both pre-construction acoustic design advice and  we can also help if your building has failed the Part E sound test. We also offer onsite inspection services to ensure that the sound insulation elements are being installed as per manufactures guild-lines.

If your require sound insulation testing and/or you would like acoustic design advice on your project, please contact us now at info@aptsoundtesting.co.uk.

Sound Testing to Comply with Lease Conditions

Sound Testing to Comply with Lease Conditions

Many people unknowingly fail to abide by the lease agreement as they may not know that there is usually a condition that states that they need to employ an acoustic company prior to making any changes to the floor of their apartment. The lease conditions often states that you need to undertake sound insulation testing prior to the commencement of works and upon completion of works.

In many cases their neighbour/s may complain that they can hear extra noise, this is often due to the fact that they may have changed the floor finish from carpet to wood. Unless extra acoustic design considerations are taken into account it usually results in an increase of extra airborne and impact noise being heard in unit below.

Sound_Testing_for_Lease_Agreements

Even if the floor assembly has been designed and constructed to provide adequate airborne isolation, impact noise can still be a major problem. If the finished floor surface had previously been carpet, the carpeting and underlay will normally provide a good degree of impact sound isolation. On the other hand, when the finished floor is floor is constructed in hardwood, stone or ceramic tile. Achieving good impact sound isolation requires much more attention.

If you think you may have a problem with sound in your dwelling and or you have encountered complaints from a neighbour due to modifications you have made to the floor partition then please contact us now. In all cases try be sure to describe the 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 subsequently find a solution.

In many cases, due to the complexity of acoustical and noise problems due to varying constructions, it is impossible to cover all problems in a short article such as this; however in our experience if we are employed from the beginning of a project, it usually results in compliance with Building Regulations Part E and /or compliance with your leasehold agreement, which may avert costly legal battles at the end of the project.

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

 

Sound Testing for Compliance with Lease Conditions

Sound Testing for Compliance with Lease Conditions

If you own or manage an apartment it has a lease agreement that has conditions relating to the changing of the floor construction, then you may require Sound Testing for Compliance with Lease Conditions. We undertake many leaseholder sound tests throughout London and the South East and offer a ‘4 step acoustic package’  to satisfy your lease conditions comprising of the following:

  1. Sample Sound Testing of the existing construction. This offers an accurate overview of the acoustic performance of the existing floor partition/s prior to the commencement of construction works. It also enables us to offer a targeted acoustic design using the sound insulation performance of the existing construction.
  1. Acoustic design review – once we have the performance figures from the sample sound testing have been established, we can forward a design that should improve the performance of the existing floor partition – even if you are changing the floor from a carpet to engineered timber floor finish!
  1. Site Visit – This allows us to check that the installation team is installing the acoustic materials as per manufacturer’s guidelines.
  1. Final Precompletion Sound Testing in-line with Approved Document E. This provides an accurate overview of the acoustic performance of the upgraded partition/s, the results of which can be handed over to the relevant person for sign off.

In most cases complaints are usually raised from impact noise such as foot fall from hard bottomed shoes etc. this is accentuated when the unit above has changed their floor finish from carpet to wood.

Sound_Insulation_Testing_Equipment

If you think you may have a problem with sound in your dwelling and or you have encountered complaints from a neighbour due to modifications you have made to the floor partition then please contact us now we can provide our ‘3 step plan’ to satisfy your units lease conditions, then please contact us now at: info@aptsoundtesting.co.uk  or phone Darren directly on 07775623464.

Sound Testing for Leasehold Compliance

Sound Testing for Leasehold Compliance

Clients often get in touch with us when they have run into trouble whilst undertaking refurbishments to their London apartments. In many cases they have a lease agreement that requires a sound insulation test be undertaken prior to the commencement of works and secondary sound testing upon completion of the works. Most people do not adhere to their lease agreements because they haven’t read the conditions which may result in very costly modifications to the finished floor finishes at the end of the project.

Noise_Problems_Failed_Sound_Testing

Many lease agreements contain something similar to the following conditions: ‘If the tenant wants to change the floor construction within his dwelling he shall’:

  • Commission an independent acoustic consultant to carry out a pre-installation test, design the new acoustic installation and carry out a post installation test and provide the results to the landlord’s surveyors for approval; and
  • Invite the Landlord’s surveyor to inspect the acoustic insulation before it is concealed; and
  • Accept that the Landlord, whilst granting this Licence, does not accept any responsibility for the design or performance of the insulation provided and that if any issues arise, the Tenant will address these immediately. In the event of reasonable complaint being upheld by the Landlord or his agent concerning noise affecting other Tenants within The Building, the Tenant will arrange for carpeting (the provision of which shall be determined by the Landlord) to be positioned and maintained at the Tenant’s sole cost.

To overcome potential problems and neighbour disputes we can undertake Sample Sound Testing of the existing construction. This offers an accurate overview of the acoustic performance of the existing floor partition/s prior to the commencement of construction works. we can then undertake an acoustic design review  to improve the performance of the existing floor partition – even if you are changing the floor finish from carpet (soft finish) to engineered timber floor (Hard finish) We can also undertake a site visit – This allows us to check that the installation team is installing the acoustic materials as per manufacturer’s guidelines. We can then undertake Precompletion Sound Testing in-line with Approved Document E. This provides an accurate overview of the acoustic performance of the upgraded partition/s, the results of which can be handed over to the relevant person for sign off.

If you are about to make changes to your apartment, and you think you may require Sound Testing for Leasehold Compliance and/or our acoustic test and design service, then please contact us now at: info@aptsoundtesting.co.uk  or phone Darren directly on 07775623464.

The Difference Between Laboratory and Site Sound Testing

The Difference Between Laboratory and Site Sound Testing

Many suppliers of acoustic insulation products quote laboratory sound test results  to demonstrate the performance of their systems. This often causes considerable confusion regarding how well products will perform as there are usually large differences between the laboratory and site conditions. For instance laboratory sound tests do not take account of flanking sound and therefore produce sound insulation figures that would be very difficult to achieve on site.

sound testing

Despite site contractor’s best endeavours, it is extremely difficult to build to the stringent exacting standards of the test laboratory. When the construction assembly is undertaken in the lab, it has gone through an exacting installation technique prior to the sound test, which is also a contributing factor why better sound testing levels are achieved.

Throughout the acoustic installation the manufacturer’s guidance is followed to the letter by the lab technicians. Although, this should be replicated on site, it seldom is due to time constraints etc. and so a design which can be easily in excess of the requirements of approved document E, can often lose approx. 8-10dB compared to the laboratory results. Unfortunately there may be many reasons for poor sound test results such as poor quality site installation as well as other on-site issues where cost, time and programming constraints may come into play.

architect drafting a house blueprint

architect drafting a house blueprint

One important thing to consider is that most building structures will be subject to varying amount of flanking sound, so field sound test data should show the real performance of a system in a building. Laboratory sound insulation tests simply measure sound and do not account for flanking sound transmission.

If you are worried about your projects acoustic design and/or have questions about the precompletion sound testing, please don’t hesitate to contact us now at: info@aptsoundtesting.co.uk or Darren direct on 07775623464. 

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.