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 A-B

Acoustic Terminology A-B

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 along with a quick explanation:

 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.

Acoustic_Site_Survey

If you have a project that requires acoustic design and/or sound 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

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.

Good Acoustic Design Detailing

Good Acoustic Design Detailing.

Careful consideration to acoustic design detailing should be used from the offset of the project, whether it’s a new build or conversion project, 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.

architect drafting a house blueprint

To help our clients achieve a successful sound test at the first attempt, we offer a full acoustic package which consists of the following elements:

  • Site Survey Visits – to let us view the existing site construction. This allows us to check for potential problematic construction such as inclusion of lightweight blocks in the existing construction. It also lets us check that the installation teams are installing the acoustic materials as per manufacturer’s guidelines.
  • Sample Sound 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 using the sound insulation performance of the existing construction.
  • Acoustic Design Review – a full design review of the proposed developments party walls and floors.

There are many design considerations that need to be accounted for when allowing for your project/s, they are:

  • 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.
  • Ensure all penetrations are fully sealed where they terminate through floors and they are adequately boxed with acoustic quilt and two layers of plasterboard.

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.

Designing for Sound Insulation

Designing for Sound Insulation

Many of the dwellings in throughout the UK consist of large houses or office blocks that have been converted into flats. Unfortunately during the design stage of the project designing for sound insulation is not always shown the highest priority, so many converted dwellings fail their precompletion testing.

Acoustic_Design_Service

We have helped many of our clients achieve compliance with Part E, by undertaking some simple steps. We can undertake an initial sample sound test of the existing wall and floor construction to ascertain the existing sound insulation levels. Once we have established the sound levels for the existing construction, we can then look at extent of the acoustic upgrades to attain Part E Compliance. This is much more effective than just forwarding an acoustic design that may be to excessive and expensive, especially if the existing floor and/or wall only needs to improve by a minimal amount such as 1-3dB. By having the existing sound levels of the partitions we can recommend targeted, acoustic upgrades to comply with Building Regulations Part E.

Even though the sound insulation levels required to pass Part E for refurbishment projects are less stringent than new build projects – instead of 45dB for airborne its 43dB (2dB less), and for instead of 62dB for Impact Sound Testing its 64dB on new build (2dB more) it is still essential that the acoustic design is shown the highest priory from the start of the project.

Noise_Problems_Failed_Sound_Testing

In our experience, refurbishment projects usually achieve 30-35dB for airborne sound and 70dB for Impact Sound during the sample sound test – 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 major acoustic improvements must be made.

On all new or converted developments, is it essential that good acoustic design is addressed right from the start of the refurbishment project, so the building passes the sound testing at the first attempt and prevents delays in handover.

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

Impact Sound Insulation Testing

Impact Sound Insulation Testing

Impact sound transmission testing is undertaken to floors only. This test is different, a calibrated Norsonic ‘tapping machine’ which comprises of five ‘hammers’ driven up and down by a cam and electric motor is used to “tap” the floor surface by applying a known force on the floor structure. The machine is placed in several pre-determined positions. The resulting noise is measured in the dwelling below, using a sound level meter.

Impact Sound Testing

Thereafter, background noise measurements are made using a class 1 sound level meter in the receiving room and are used to apply appropriate corrections for external sound such as traffic noise. Similarly the reverberation time (the time taken for sound to decay by 60dB) is measured within the receiving room using the sound source and a sound level meter to determine the corrections that must be applied to account for the characteristics and absorptiveness of the room.

The measured noise levels in the receiving room are corrected for background and reverberation characteristics determine the impact sound insulation performance of the floor. For the impact noise the lower the measured level, the better the performance as less sound is being transmitted into the dwelling below.

The time taken to undertake sound testing varies from project to project as no site is exactly the same. Taking into account the standard site conditions impact testing is usually undertaken as part fo a 6 pack test, consisting of  2 airborne wall, 2 airborne floor and 2 impact sound tests. A standard 6 pack test will usually take between two  and three hours, although this is dependent on our engineers having full free uninterrupted access between all the units/rooms under investigation.

If you require sound insulation testing, and/or acoustic design advice then please contact us now at info@aptsoundtesting.co.uk  or phone me (Darren) directly on 07775623464.

Why do my Floors Squeak?

Why do my Floors Squeak?

We often receive complaints from clients in regards to their floors creaking. This is often because the Joists are often spaced too far apart, which can result in a reduction in floor stiffness. Over-notching of joists can also lead to a reduction in floor stiffness and also potential squeaking. Although the floors may pass the airborne and impact sound testing, however it won’t stop the squeaking of the floors under the extra load imposed by people walking above.

sound_transmission_through_floors

Other problems may be down to the contractor using 12mm floor boarding instead of 18mm to the top of the joists, again this may allow the boards to move and squeak. It may also be down to the chipboard not sitting level across the joists, this may down to the  joists being installed at slightly the wrong level or a joist hanger may have been hit or come loose during the build. If the joist has been built into the wall the bearing could be unsatisfactory. it may be as simple as a missing joist, or cut edge unsupported or an over span on the joists.

  • Incorrect bridging of resilient layer by over-long screws/nails
  • Fixings connecting ceiling boards to resilient bars should not bridge to joists
  • Extra wide joist spacing that reduces floor stiffness
  • Platform floor resilient layers damaged by inserting pipes and services within the layers
  • Reduction in stiffness due to use of joist hangers
  • Ceiling boards not staggered
  • Over-notching of joists for services reduces floor stiffness
  • Incorrect omission of flanking strips at floor edge perimeters.

In most cases, due to the complexity of acoustical and noise problems along with an overwhelming variety of material designs and combinations due to varying constructions, it is impossible to cover all problems in a short article such as this; however 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.

If you have a project that requires acoustic design advice and/or sound insulation testing, then please contact us at: info@aptsoundtesting.co.uk or phone me (Darren) 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 stipulates that one set of sound tests needs to be undertaken for every ten flats or houses, provided the construction system is the same, if it’s not then you may be required to undertake a set of tests on each type of construction.

A set means 6  sound tests, this 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. Wherever possible tests must be undertaken between habitable spaces (e.g. bedrooms and living rooms. Here is a quick summary of the amount of tests required per type of project.

Semi-Detached Houses:

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

Sound_Testing_Semi_Detached_House

Flats (Up to 10 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.

Sound_Testing_Flats

Rooms for Residential Purposes (up to 10 Rooms)

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

Sound_Testing_Hotels

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.

Here is a link to our website www.aptsoundtesting.co.uk  which shows you our full range of services in compliance with the latest Building Regulations.

Tips to Pass your Sound Insulation Test

Tips to Pass your Sound Insulation Test

Our clients often get asked for tips in regards to passing their sound testing; here are a few tips to help you pass Building regulations Part E:

  • 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.
  • Ensure that you don’t position sockets back to back in acoustic partitions walls.

architect drafting a house blueprint

There are many factors to consider when considering good acoustic design, and they are usually split up into five key factors. If used together or in various combinations they will improve sound insulation properties over a wide range of frequencies. The main factors are:

  1. Mass
  2. Isolation
  3. Absorption
  4. Resilience
  5. Stiffness

Another potential problem can also be down to noise flanking transmission, especially in existing buildings where you are planning to convert offices/large houses into flats. Here are just a few of the potential noise flanking areas:

  1. Structural Steels
  2. Windows built very close to Internal partitions
  3. Inner leaf of the external wall
  4. External wall cavities
  5. External façade or outer leaf
  6. Roof structure

If you click on this link: http://blogyourbusiness.co.uk/designing-for-sound-testing-in-london/ it will take you to the corresponding article which should help explain this in more detail. Here is a link to our website www.aptsoundtesting.co.uk which shows you our full range of services in compliance with the latest Building Regulations. 🙂

If you would like more information on our acoustic services, please don’t hesitate to contact me at: info@aptsoundtesting.co.uk or call me (Darren) direct on 07775623464.

Good Acoustic Design for Sound Testing

Good Acoustic Design for Sound Testing

To attain the standards stipulated within Building Regulations Part E, careful consideration should be shown to your buildings acoustic design  from the start of the project; however this requires different construction techniques and acoustic design detailing for new and build and conversion projects. With new build properties you have a blank canvas in terms of the overall design whereas conversions usually require you to work with the existing construction which can be quite difficult if the existing construction is not acoustically robust.

sound_transmission_through_floors

To try and overcome the problems with attaining Part E for your conversion project, we now offer an acoustic design package, which contains the following elements:

  1. Sample Sound Testing – of the existing construction. This offers an accurate overview of the acoustic performance of the existing partitions; this enables us to offer a targeted acoustic design using the sound insulation performance of the existing construction.
  2. Acoustic Design Review – a full design review of the proposed developments party walls and floors taking into account the performance characteristics of the existing construction as well as the buildability and materiel cost of the acoustic upgrade.
  3. Site Survey Visits – to let us view the existing site construction. This allows us to check for potential problematic construction such as inclusion of lightweight blocks in the existing construction. It also lets us check that the installation teams are installing the acoustic materials as per manufacturer’s guidelines.
  4. Final Precompletion Sound Testing  – in compliance with Building Regulations Part E to help achieve building control sign off.

We have undertaken hundreds of design reviews around London and the South East with our clients achieving  a 100% pass rate where the acoustic review has been followed. If you would like some more information in regards to our acoustic services and/or sound testing services please visit our website at info@aptsoundtesting.co.uk, or contact us at: info@aptsoundtesting.co.uk or call me (Darren) direct on 07775623464.