The Pathway to Good Acoustic Design

The Pathway to Good Acoustic Design 

There are many important acoustic design considerations when designing for apartment blocks, which require both airborne wall and floor and impact floor testing. here are a few of the main considerations:

  • Ensure all penetrations are fully sealed where they terminate through floors and they are adequately boxed with acoustic quilt and two layers of plasterboard.
  • Avoid the use of lightweight blocks in the inner envelope construction as sound will travel both vertically and horizontally from dwelling to dwelling.
  • The use of resilient suspended ceilings will help improve the performance of the floor partition.
  • Ensure all support steels/timbers are carefully boxed out where they travel from flat to flat vertically and horizontally.
  • Use a high quality resilient acoustic membrane on top of the floor to improve the impact performance of a floor.

Sound_Testing_Flats

By simply constructing a good separating wall or floor this may not in itself provide sufficient sound insulation to comply with Building Regulations Part E as the junctions of each separating wall and/or floor with other parts of the building are as equally important. One of the main problems with partition failure is down to noise flanking, this can occur via construction components such as:

  • The internal partitions
  • The inner leaf of the external wall
  • The external wall cavities
  • The external façade or outer leaf
  • The roof structure
  • 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.

architect drafting a house blueprint

architect drafting a house blueprint

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 Some cases, sound test failure can also be down to the poor workmanship rather than the acoustic design, that is why we offer a full acoustic package which includes for site survey visits; that way we have the acoustic design and onsite construction covered, reducing the chance of sound test failure.

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 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 F – L

Acoustic Terminology F – L 

Our previous blog explained the C-F of acoustic terminology, this blog further covers F – L.

Following on from our previous blogs which gave a brief description of

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 skirtings.

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.

Isolation

This is a strategy to limit the number and type of rigid connections between elements of construction.

 L’nT,w

This is the weighted standardized impact sound pressure level. A single-number quantity (weighted) to characterise the impact sound insulation of floors, in accordance with BS EN ISO 717-2: 1997.

If you have a project that requires our acoustic design service and/or sound insulation testing please contact us at info@aptsoundtesting.co.uk or youhone Darren Direct on 07775623464. You can also visit our website at: www.aptsoundtesting.co.uk

 

Acoustic Design Service in London

Acoustic Design Service in London.

If you have a property that has failed its sound testing in London, it may be down to number of reasons with the acoustic construction. 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. We can offer advice on cost effective wall and/or floor upgrades, also taking buildability and material cost into account. Our acoustic design reviews are easy to follow for the site construction staff.

Room-Integrity-Design

By utilising our extensive knowledge of different materials and construction methods, we have had no sound test failures where our acoustic upgrades have been incorporated into the site construction.

London Sound testing usually needs to be carried out between pairs of rooms separated by party walls and/or floors. Most sound tests are carried out 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 studies, kitchens and dining rooms.

To help control noise issues APT Sound Testing can undertake UKAS accredited Part E sound testing in London and throughout the South East. Our sound test engineers carry all the latest class 1 acoustic equipment. We provide full UKAS accredited air and sound testing in London, so our clients can be sure that all testing is completed to a strict ISO quality controlled standard

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

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.

Good Acoustic Design Considerations

Good Acoustic Design Considerations

In our experience careful consideration to acoustic design should be undertaken from the start of the project, if this process is followed it usually results in successful precompletion sound testing in compliance with Building Regulations Part E.

In many cases sound test failure can be down to the poor workmanship rather than acoustic design, that is why we offer a full acoustic package which includes for site survey visits; that way we you can be safe in the knowledge that you have the acoustic design and onsite construction covered, reducing the chance of sound test failure.

sound testing equipment

Here are some simple acoustic design tips:

  • Ensure all penetrations are fully sealed where they terminate through floors and they are adequately boxed with acoustic quilt and two layers of plasterboard.
  • Use resilient acoustic hangers within the ceiling design to provide isolation between materials.
  • Avoid the use of lightweight blocks in the inner envelope construction as sound will travel both vertically and horizontally from dwelling to dwelling.
  • Ensure all support steels/timbers are carefully boxed out where they travel from flat to flat vertically and horizontally.
  • Use a high quality resilient acoustic membrane on top of the floor to improve the impact performance of a floor.

In our experience by simply designing and constructing a good separating wall or floor it may not provide sufficient sound insulation to comply with Building Regulations Part E as the junctions of each separating wall and/or floor with other parts of the building are as equally important. One of the main problems with partition failure is down to noise flanking, this can occur via construction components such as:

  • The internal partitions
  • The inner leaf of the external wall
  • The external wall cavities
  • The external façade or outer leaf
  • The roof structure
  • The foundations.

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 and lightweight materials have been used in the wall construction. If the acoustic consultant has not been made aware of the existing construction it may increase the chance of sound testing failures.

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.

Sound Testing for Leasehold Agreements

Sound Testing for Leasehold Agreements

One of the main reasons for neighbour disputes is down to the fact that floor modifications may have taken place without the flat owner, first consulting his/her leasehold agreement. In many cases the lease agreement contains something similar to the following conditions:

Sound Testing through Floors

Part-E-Sound-Testing

‘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;

We offer a comprehensive acoustic service to let our clients comply with their leasehold agreements.

  • Pre-works 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.
  • 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!
  • Site Survey Visit – This allows us to check that the installation team is installing the acoustic materials as per manufacturer’s guidelines.
  • 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.

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

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.