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.

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.

SOUND INSULATION TESTING in LONDON

Sound Insulation Testing in London

APT Sound Testing have a massive amount of experience when it comes to undertaking  sound insulation testing in London. We have the necessary know how and onsite experience to carry out sound insulation testing on a new build or conversion project throughout London for a most competitive prices.

Our engineers carry out the airborne and impact sound test measurements in compliance with Part E of Building Regulations. We have previously undertaken hundreds of sound tests to new build and conversion projects. we also undertake detailed design reviews to ensure our clients achieve a successful sound test.

NoiseFlankingWall

Our engineers also understand the extra coordination that’s required to test within central London, whether its restricted access and/or parking we have it covered. Many other companies that are based outside London literally double their fees when undertaking sound testing in the capital; as we have an office in London we can afford to charge the same flat fee as we do across the rest of the UK.  Also as we are based in London we can usually arrive on site at the agreed time which often minimises delays to planned noisy works on site. We aim to arrive early and leave early.

We undertake London sound testing on all types of projects from simple flat conversions to large new apartment block developments containing many hundreds of flats. We also undertake sound testing where a lease holder dispute has arisen, which is quite common in London. We can undertake sample sound testing to highlight the existing sound insulation performance of the dividing wall and/or floor partitions to allow for targeted acoustic design to keep cost and delays to a minimum.

If you would like more information on our London Sound Insulation Testing package please contact us now at info@aptsoundtesting.co.uk or call me directly on 07775623464.

How Many Sound Tests Do I Need On My Project

How Many Sound Tests Do I Need On My Project?

Our clients often ask ‘how many sound tests do I need on my project’. Part E stipulated that one set of sound tests needs to be undertaken for every ten flats or houses, provided the construction system is the same. A set means that the test should include two locations where the party element (wall or floor) is tested. This is equivalent to two individual tests when assessing the performance of a wall this means 2 airborne wall, 2 airborne floor and 2 impact sound tests as a minimum wherever possible. All tests must be undertaken between habitable spaces (e.g. bedrooms, living rooms) and not to or from common spaces such as stairwells and corridors.

Acoustic Design Advice

Approved Document E 2003 also states that a minimum of 10% of all party walls and floors is sound tested for every type of construction or sub-group, this means where there a variations in the construction of the floors and/or walls may occur then further testing may be required. The amount of sound tests required for each type of development is:

Houses:

On houses two airborne sound insulation tests on a pair of separating walls would be required.

Flats:

On flats a 6 Pack would normally be required, this would usually comprise of two airborne sound insulation tests on separating walls; two airborne sound insulation tests of separating floors and two impact sound transmission tests of separating floors

Rooms for Residential Purposes:

On student accommodation, hotel rooms & care homes a set of tests would usually comprise of one airborne sound insulation test of a separating wall; one airborne sound insulation test on a separating floor and one impact sound transmission test of a separating floor.

If you are unsure of the amount of sound tests required on your development, please contact us now at: info@aptsoundtesting.co.uk or call me direct on 07775623464.

Minimising Noise Flanking Transmission to Pass Sound Tests

Minimising Noise Flanking Transmission to Pass Sound Testing

One way to reduce the chance of noise flanking transmission/s to pass the sound testing for Part E of Building Regulations is to carefully look at the acoustic details at the design phase of the project, as well as good planning and workmanship thereafter. Unfortunately, by simply specifying high performance wall and floor partitions between dwellings is no guarantee to a sound isolation and subsequently successful sound testing.

Sound travels along the path of least resistance between rooms, usually through any penetrations/air leaks or through rigid and poorly isolated connections in the structure itself, these routes are called noise flanking paths.

  • Wide gaps below doors provide a flanking noise pathway.
  • Air leakage around partition walls at the wall/ceilings junction.
  • Sound leaking through ‘lightweight’ hollow-core doors.
  • Through ductwork penetrations between two rooms or boiler cupboards placed back to back.
  • Fixtures & Outlets – Light Switches, Telephone Outlets, and Recessed Lighting Fixtures (if penetrations have been cut back to back with the opposite dwelling under test)
  • Poor sound isolation between floors, if subfloor wooden planking extend beneath the dividing floor partition and into an  adjoining dwelling this will form a sound flanking pathway.
  • Framing connections that include solid framing members passing between building areas such as oak beams where large old houses have ben subdivided.
  • Poor isolation to partition abutments to adjoining walls, ceilings, floors
  • Service penetrations behind back to back kitchens, such as soil stacks, waste and recessed pipework.
  • Plumbing Chases – Junctures Between the Walls & Floor Slab Above or at the Exterior Wall Juncture (this should be filed with mortar etc. to add mass to this weakened area)
  • Through Structural Steel (structural steel beams are often a major cause of noise transmission as plasterboard is often fixed directly to the steel without sound breaks)
  • Dividing Floors – Through Floor and Floor Joist Space (if insulation has not been installed or direct fixing to joists without a drop ceiling below the partition under test)
  • Dividing Ceilings – Above and Through the Ceiling Space (where an adequate acoustic break has not been carried on through the ceiling void).
  • Recessed light fixtures that pass through the plasterboard and acoustic insulation.
  • The wrong fixings used during the installation of resilient channel systems, i.e. drywall screws that are too long that penetrate into the ceiling joists.
  • Window noise transmission due to poor performance glass etc.
  • Door noise transmission due to the inclusion of lightweight hollow core doors, with large gaps to the bottom of the door threshold.
  • On bathroom partitions, install drywall all the way to the floor before installing the bath and seal all plumbing penetrations through walls with a flexible sealant.

NoiseFlankingWall

If the wall/floor partitions have poor isolation and can greatly reduce the effectiveness of soundproofing efforts and can lead to sound test failures. Even if your construction allows for ‘robust’ sound insulation ratings, it will be rendered useless, if sound can pass easily through service penetrations in the walls and floors or through lightweight doors.

APT Sound Testing offers both pre & post construction design solutions to achieve the required sound isolation requirements of Part E of Building Regulations.

We offer an acoustic onsite inspection service to ensure that the sound insulation elements are being installed as per manufactures guide lines and the quality of the workmanship is consistent with ‘best practice’ noise control procedures and we have the technical experience to help identify and rectify your soundproofing or noise flanking problem/s.

If you would like more information in regards to sound testing, please contact us at: info@aptsoundtesting.co.uk or call us direct on 07775623464

Should I inform my Neighbours of the Sound Testing?

Should I inform my Neighbours of the Sound Testing?

Your neighbours will need to be contacted if access is required to their properties to complete the sound testing. Also as the sound levels produced during the test are very high it would be ‘neighbourly’ to inform the residents as they are likely to hear the test. If your project is a new build and/or a change of use and its built onto an existing property then chances are you will be required to undertake an airborne wall test. We recommend that you check this with your local building control officer prior to the testing so you can plan access to the neighbouring properties accordingly.
Can I Observe the Sound Testing?

sound testing equipment

APT Sound Testing will happily give you a brief demonstration and overview of the test, if so required; however, during the actual sound testing, we will need to follow stringent rules which restrict extra personnel within the test areas.
I want peace of mind that I’ll pass the sound testing

Poor Sound test results can occur for many reasons. The most common factor influencing acoustic performance is poor workmanship. Detailing is critical to maximising on site acoustic performance, especially in floor and wall isolation and appropriate party wall and floor construction. If inadequate provision for the isolation of materials is not undertaken

Should I inform my Neighbours of the Sound Testing? 

The Correct Site Conditions for Sound Testing

 The Correct Site Conditions for Sound Testing 

To undertake accurate sound testing, we require the site noise levels to be kept to a minimum. During the sound insulation testing, our equipment produces high levels of noise – between 100-110dB! However, to record accurate test measurements, relatively quiet conditions are required on site throughout the testing. Any site operatives working in the testing area will have to leave temporarily and any noisy works in the vicinity of the test areas including external site activity such as groundworks, drilling and banging will need to be halted. 

We also require full access to all the rooms being tested. We provide a full testing schedule within our quotation which will clearly identify suitable couplings of test rooms which may require access to adjoining neighbours dwellings to enable us to complete the sound testing

APT Sound Testing will try to schedule the sound testing with you at a time when noise can be controlled to achieve the best possible testing results. 

sound testing

What’s the Duration of the Sound Testing? 

The time taken to undertake sound testing varies from project to project as no site is exactly the same. Taking into account standard site conditions a set of tests on houses -two airborne walls will take one to two hours. A six pack of tests on flats – 2 airborne walls, two airborne floors and two impact tests will take between two to three hours. Throughout the sound testing, we will require full free uninterrupted access to the units/rooms in all test areas. 

If you require more information on sound testing, please contact us now at info@aptsoundtesting.co.uk or phone me direct on 07775623464.

Our Pathway to Successful Sound Testing

Our Pathway to Successful Sound Testing

Sound Insulation Site Audits

We can undertake acoustic site audits, to let us view the existing site construction. This allows us to check for potential problematic areas such as the inclusion of lightweight blocks within the existing wall construction. It also lets us check that the installation teams are installing the acoustic materials as per manufacturer’s guidelines, thus avoiding crucial onsite mistakes. In our experience a sound test failure is often due to the poor workmanship rather than the actual design. The site survey visits negate the risk of sound test failure.

We can also undertake sample sound insulation testing of the existing construction. This offers an accurate overview of the acoustic performance of the existing partitions, which enables us to offer a targeted acoustic design which takes into account the performance of the existing construction.

 Acoustic Design Advice

Acoustic Defect Diagnosis & Remedial Advice

With many years’ experience in building acoustics, we are able to diagnose the reasons for the sound test failure and recommend a cost-effective solution. Often, the reasons for the partition failure are obvious to the test engineer in which case the advice will be minimal and subsequently the cost for acoustic design advice will be minimal. Sometimes, there are more technical issues which require more detailed diagnosis and invasive investigation, such as large amounts of noise flanking due to serious design faults, e.g. poor material isolation.

Precompletion Sound Testing

To help enforce good acoustic design principles pre-completion sound testing was introduced July 2003, this resulted in all new build properties and conversions which were built after this date are require 10% of each party wall/floor construction type to be tested.

Precompletion Sound Testing is carried out between pairs of rooms separated by party walls or floors. The two ‘habitable’ areas that usually require sound testing are living rooms and bedrooms, although other rooms can be tested if this is not possible, i.e. kitchen to bedroom.

sound testing equipment

If you need sound insulation testing and acoustic design, please don’t hesitate to contact us at info@aptsoundtesting.co.uk  or call me on 07775623464

IMPROVING SOUND INSULATION ON LONDON REFURBISHMENT PROJECTS

IMPROVING SOUND INSULATION ON  LONDON REFURBISHMENT PROJECTS

Many of our new clients ask ‘ how can we improve our sound insulation on our London Refurbishment projects’. One of the main problems is that a large number of the dwellings in London, consist of flats converted from large Victorian houses. Unfortunately at the time of the building conversion, designing for sound insulation was not a high priority 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.

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. By isolating the different materials may not be enough its own and you may need to improve the mass of the partition as well.

Video Showing Main Noise Transference Points Through Existing Partitions.

Improving Existing Floor Partitions

In our experience of undertaking hundreds of sound insulation tests in London, refurbishment projects usually achieve 30-35dB for airborne sound and 70dB for Impact Sound, if the existing construction has not been acoustically upgraded. These figures do not meet the required 43dB & 64dB as stipulated in Part E of Building Regulations. As sound double every 10dB this is a massive failure and acoustic improvements must be made. Many existing construction consist of a similar construction as shown in as detail 1 below.

Detail 1: Existing Floor Partitions Rated At Approx. 30dB

 Failed_sound_Testing_Due_to_existing_floor_Construction_

Acoustic Improvements to Existing Floor Partitions

To reduce airborne and impact sound transmission this usually means adding density and isolation to the floor construction. This can be as simple as adding a drop ceiling consisting of 125mm timber frame. The top of the frame must be a minimum of 25mm below the existing ceiling finish – such as lathe and plaster. Then, to the inside of the timber frame add 100mm of Acoustic Wool and two layers of sound-board tacked to the bottom of the timber frame – all boards to be lapped. This should improve your sound test results by approx. 10-15dB depending on the existing site conditions and quality of the installation. Detail 2 shows this in more detail.

Detail 2: Acoustic Flooring Partition Upgrade

Simple_floor_upgrade_to_Pass_Sound_Testing

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

The Method for Sound Insulation Testing

The Method for Sound Insulation Testing

The method for testing for airborne and impact sound insulation testing methods is clearly presented in BS EN ISO 140-parts 4 & 7: 1998. The sound insulation rating methods that follow are defined in:

 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.

 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 – 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.

sound testing equipment

APT Sound Testing is UKAS accredited to undertake both Sound Insulation Testing and is also accredited to ISO 17025:2005 ‘General requirements for the competence of testing and calibration laboratories’. If you would like more information in regards to sound insulation testing and/or acoustic design, please contact us now at: info@aptsoundtesting.co.uk or call us on 07775623464