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.

sound_transmission_through_floors

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.

Sound Testing on Conversion Projects

Sound Testing on Conversion Projects

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

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

Acoustic Design Advice

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

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

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

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

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

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

Sound Testing Services for New Dwellings

Sound Testing Services  for new dwellings

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

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

sound testing equipment

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

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

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

Sound Insulation Testing Terminology (3 of 3)

Sound Insulation Testing Terminology (3 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 last blog in the series:

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.

sound testing

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.

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

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

Sound Test Terminology (1 of 3)

Sound Test Terminology (1 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 first of three blogs:

Absorption – This is the conversion of sound energy into heat, often by the use of a porous material.

Absorbent Material – This is a material that absorbs sound energy, such as acoustic mineral wool.

Airborne sound – This is sound which is propagated from a noise source through the medium of air. Examples of these are speech and sound from a television

Airborne Sound Transmission – This is direct transmission of airborne sound through walls or floors. When sound energy is created in a room, for instance by conversation, some of the energy is reflected or absorbed by room surfaces but some may set up vibrations in the walls and floor. Depending on both the amount of energy and the type of construction, this can result in sound being transmitted to adjacent parts of the building.

Air Path – This is a void in construction elements, which adversely affects the performance of sound resisting construction. Examples of air paths include incomplete mortar joints, porous building materials, gaps around pipes and shrinkage cracks – this can also effect the air tightness results.

Bonded resilient cover – This is a thin resilient floor covering normally of minimum 3-5mm thickness, which is bonded to the isolated screed surface to reduce impact sound transmission such as footfall noise, however it has a lesser effect when it comes to airborne noise.

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.

Acoustic_Ceiling_Upgrade

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

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

Broken Down Rating Methods for Sound Testing

Broken Down Rating Methods for Sound Testing 

The sound insulation rating methods that follow are defined in:

Sound insulation 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.

sound testing equipment

The sound insulation rating methods that follow are defined in:

 Rating Method – RW

This single figure rating method is the rating used for laboratory airborne sound insulation tests. The figure indicates the amount of sound energy being stopped by a separating building element when tested in isolation in the absence of any flanking paths.

 Rating Method – DnTw

The single figure rating method that gives the airborne sound insulation performance between two adjacent rooms within a building as measured within site conditions. The result achieved is affected not only by the separating element also by the surrounding structure and junction details.

 Rating Method – Ctr

The Ctr adaptation term is a correction that can be added to either the RW (laboratory) or DnTw (site) airborne rating. The Ctr term is used because it targets the low frequency performance of a building element and in particular the performance achieved in the 100 – 315 Hz frequency range. This term was originally developed to describe how a building element would perform if subject to excessive low frequency sound sources, such as traffic and railway noise. This rating is expressed as RW + Ctr and allows the acoustic designer to critically compare performances. The rating method has not been universally welcomed. Some

acousticians believe that the method is too crude as it only considers the low frequency performance, and because site measurements at low frequencies are prone to difficulties, which can lead to a lack of confidence in the results achieved.

 Rating Method – Lnw

This single figure rating method is the rating used forclaboratory impact sound insulation tests on separating floors. The figure indicates the amount of sound energy being transmitted through the floor tested in isolation, in the absence of any flanking paths. With impact sound insulation, the lower the figure the better the performance.

Rating Method – LnTw

The single figure rating method that is used for impact sound insulation tests for floors. The figure indicates the sound insulation performance between two adjacent rooms within a building as measured on site. The result achieved is affected not only by the separating floor but also by the surrounding structure, e.g. flanking walls and associated junction details.

Rating Method – Dncw

The single figure laboratory rating method, which is used for evaluating the airborne sound insulation performance of suspended ceilings. Laboratory tests simulate the room-to-room performance of the suspended ceiling when a partition is built up to the underside of the ceiling with sound transmitted via the plenum.

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

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.

Failed_sound_Testing_Due_to_existing_floor_Construction_

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.

Noise Flanking Through Steel Columns

Noise Flanking Through Steel Columns.

Unless Steel Columns or beams are isolated from the surrounding wall/floor partition it can lead to noise flanking, particular hollow steel columns. Steel can also provide a strong path for structural impact transmission due to its dense nature.

Pre-conversion sample sound tests should be able to identify whether any columns act as a significant transmission path and whether any acoustic treatment is required to remedy the situation. It may not be necessary to treat the column in all dwellings if flanking is limited, however in many instances the columns will need to be acoustically boxed to prevent sound test failure.

ACOUSTIC_DESIGN

One such acoustic treatment for steel columns or beams would be to construct a free standing metal or timber stud partition around the column, incorporating 50mm insulation quilt and sheeted with two layers of gypsum-based board. Where columns pass through separating floors, as in old bonded warehouses, the junction between column and floor should be well sealed not only for sound insulation but also for fire. The column linings should be double lined with gypsum-based board (minimum mass per unit area 10kg/m2).

Timber beams do not significantly affect the sound insulation performance of a separating floor. However, if a beam has been installed for strengthening, the boxing around the beam may be a single sheet of lightweight board and the board may be fixed directly to the beam resulting in a noise flanking path for airborne and impact sound. This can be resolved by stripping off the boxing, packing any voids with dense mineral wool batt and re-sheeting with two layers of dense gypsum-based sound board.

We hope the above information helps you to understand the potential problems with acoustic design and pre-completion sound testing on your development. If you have a project that’s requires acoustic design advice or sound testing in London, then please contact us at: info@aptsoundtesting.co.uk  or phone us directly on 07775623464.

The two types of sound insulation testing through floors.

There are two distinct types of sound insulation testing through floors, they are:

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

In the event of  both types of sound – Airborne & Impact) are emitting excessive noise 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

We also offer an 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. Where our acoustic upgrades have been incorporated into the site construction, all the pre-completion sound tests have passed, ensuring compliance with Part E of Building Regulations.

Pre-completion sound testing has been a mandatory requirement since 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. In is usual to test 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 study’s, kitchens and dining rooms.

We also carry out a large amount of sound tests in council/housing association blocks, where the residents are experiencing excess noise between the dividing wall and floor partitions.

We provide full UKAS accredited air and sound testing in London, using the latest Class 1 equipment, 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 or sound testing in London, please contact us now at info@aptsoundtesting.co.uk or call us on 07775623464.