Successful Sound Testing in London

Successful Sound Testing in London 

From the offset careful consideration should be shown to the acoustic design detailing for both conversion and new build projects if you are to achieve a successful sound testing in London at the first attempt.

For instance many of the dwellings in London consist of flats converted from large Victorian houses. At the time of the original build some 100 years ago, designing for sound insulation was not a consideration and so many of the dwellings suffer from adverse noise transference between the floor and wall partitions. This can be extremely stressful to the occupant’s well-being is a major cause for concern.

ACOUSTIC_DESIGN

There are ways to improve the airborne and impact performance by improving the wall/floor partitions ability to reduce the amount of sound transmission from one side of a construction element to the other and subsequently  from dwelling to dwelling. By adding isolation and  mass to the floors and wall construction compliance with Part E for conversion projects can be achieved.

To help our clients achieve successful sound testing we offer the following ‘3 step package’:

  1. Sample Sound Testing of the existing building. This offers an accurate overview of the acoustic performance of the existing partitions which enables us to offer a targeted acoustic design using the sound insulation performance of the existing construction.
  2. Acoustic Design Review of the proposed developments party walls and floors to ensure acoustic details with be sufficient to pass Building Regulations Part E
  3. Site Survey Visits to check that the onsite construction is being undertaken in-line with manufacturer’s guidelines.

In our experience if the acoustic design is taken into consideration from the offset of the project, then it usually results in compliance with Building Regulations Part E.  In many cases sound test failure is down to poor acoustic design and poor workmanship, that is why we offer the 3 step process to achieve successful sound testing on your London project.

If you have a project that requires acoustic design advice or sound insulation testing, then please contact us at: info@aptsoundtesting.co.uk or phone us directly on 07775623464.

The Two Types of Floor Noise

The Two Types of Floor Noise

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

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

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

noise_flanking

The sound testing procedure is quite simple and our engineer will be happy to explain this on site. Essentially, for party walls there is one type of sound insulation test which is airborne sound test and for compartment floors there are two types of sound insulation tests which are airborne and impact sound insulation tests. The airborne sound insulation test is carried out by means of a loudspeaker emitting a steady source of noise on one side of the partition (wall or floor) to be measured. The corresponding sound level is measured on the other side of the partition. Impact sound insulation tests are carried out by means of a tapping machine placed on the floor sample to be measured and the noise measured in the room or space below

All our engineers carry out the sound test measurements in full accordance with the measurement procedures of BS EN ISO 140-4:1998[3] for field measurements with a single figure DnTw and LnTw in accordance with BS EN ISO 717. As per the new regulations the Spectrum Adaptation Ctr which is a correction factor calculated from the measured DnT.w and the corresponding third octave band DnT values.  It uses a set of weighting levels in third octave bands derived from a road traffic noise spectrum.  It is applied to airborne test results and is measured in dB.

We can carry out final pre-completion sound testing on all new build or conversion projects throughout London. If you would like advice on your acoustic design or sound testing please contact us now at info@aptsoundtesting.co.uk or call me now on 07775623464.

Sound 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

GOOD ACOUSTIC DESIGN AND CONSTRUCTION

GOOD ACOUSTIC DESIGN AND CONSTRUCTION

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

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

The overall design and construction system should therefore be considered and not just the separating wall or floor partitions.  Flanking sound transmission may in some cases be the dominant pathway between adjoining dwellings, especially in existing buildings where you are planning to convert offices/large houses into flats where there are large existing penetrations through the floors.

NoiseFlankingWall

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

APT Sound Testing can advise on all types of acoustic design, whether it’s accomplished during initial construction or during a refurbishment/renovation project.  We have the technical experience to help identify and rectify your soundproofing or noise control problem.

If you would like more information in regards to sound testing please follow our blog at: http://soundtestinguk.blogspot.co.uk or contact us at: info@aptsoundtesting.co.uk or visit our website at: www.aptsoundtesting.co.uk

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.

Poor Acoustic Design

Poor Acoustic Design 

Sound test failure is often down to poor acoustic design detailing during the design and construction phase of a project.

Sound test failure are often associated with poor acoustic design which allows noise flanking transmission through dividing floor and wall partitions. Unwanted noise travelling along flanking paths can make the building structure vibrate which causes the sound to radiate into your room. One simple cost effective solution is to build another wall or ceiling in front of the original, to offer extra isolation. For this upgrade to work you need to make sure that the independent wall or ceiling is not directly connected to the existing failed partition; so it provides isolation between materials.

ACOUSTIC_DESIGN

One of the main reasons for excessive noise flanking down to the use of lightweight blocks in the construction of the wall construction. Due to the lightweight mas of the inner wall it allows sound to transmit from dwelling to another, both vertically and horizontally. If a building has failed its sound testing, it is essential to establish if the problem is due to direct transmission, flanking transmission or a combination of both so that the most cost and time effective remedial treatment can be designed and applied to the failed partitions.

One way to reduce the chance of sound testing failures due to excessive noise flanking transmission is through a careful consideration to the acoustic design at 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.

APT offer preconstruction design advice to help you achieve successful sound testing in London in-line with Building Regulations Part E. We also offer onsite inspection services to ensure that the sound insulation elements are being installed as per manufactures guild-lines, as its not use having a robust design if it not being installed properly on site.

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.