Sound Testing to Office Conversions

Sound Testing to Office Conversions 

When it comes to refurbishment projects such as office block conversions or large houses subdivided into dwellings, we can undertake a sample sound test of the existing wall and floor construction. 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 targeted way to formulate a more cost effective and accurate acoustic  design as we know the sound insulation performance of the existing partitions.

sound testing equipment

The sound insulation levels required to pass Part E are usually 45dB for airborne wall and floors and 62dB for Impact Sound Testing on new build, however sometimes a higher target may be required in-line with the Code for Sustainable Homes; this is usually in defined in the following figures +3, 5 & 8dB, this means if its plus 5dB you will need to achieve 50dB for airborne and 57dB for impact sound testing.  Obviously if you need to comply with the Code for Sustainable Homes then special attention must be shown to the acoustic design from the offset to reduce the chance of sound testing failure.

architect drafting a house blueprint

architect drafting a house blueprint

The amount of sound testing you require depends on the size of the development. All new build properties and conversions require 10% of each party wall/floor construction type to be tested, i.e. if you have built a pair of semi-detached houses you would be required to undertake 2 airborne wall tests. If you have up to 10 flats you would require 1 x 6 pack, consisting of 2 airborne wall, 2 airborne floor & 2 Impact sound tests – known as a 6 pack)  However if you have 11 units this would rise to 12 Sound Tests or 2 x 6 pack. Also, if you have many different wall or floor types you will be required to undertake more tests to satisfy Building Regulations Part E.

There are many ways to improve the chances of passing your sound test at the first attempt, they are:

  • 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.

Due to the 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 a successful sound testing and compliance with Building Regulations Part E.

If you have a project that requires sound testing in London then contact us now, we can propose a sound testing schedule that should comply with Part E. Please contact us at: info@aptsoundtesting.co.uk or call us at 07775623464

Noise Flanking Paths

Noise Flanking Paths

To reduce the chance of sound testing failure, it is imperative that flanking transmission is considered at the design stage to reduce potential noise flanking paths. Good detailing at the design stage will minimise this effect and optimise the overall levels of acoustic privacy achieved. If designing for residential units, design advice on flanking details must be followed to maximise the possibility of achieving the specified acoustic performance. It is imperative that the design advice is followed, otherwise the site sound insulation values may not meet the performance criteria required and subsequent expensive remedial treatment may be required.

sound_transmission_through_floors

Flanking sound is defined as sound from a source room that is not transmitted via the separating building element e.g. the wall or floor partition. The sound is transmitted indirectly via paths such as external walls, windows, doors and internal corridors. One of the easiest ways of dealing with sound flanking issues is to use isolation strips around the perimeter of the partitions at the edges of floors and walls, this should be finished with acoustic sealant

One of the main reasons for flanking sound test failures is when the inner leaf of the perimeter wall is built with light weight blocks. This acts like a large snare drum and the sound simple travels straight up the wall from one flat to the flat above and/or below. Even if you have used a acoustically robust wall and/or floor partition the sound insulation testing may still fail. If you have used lightweight blocks in your onsite construction and the building fails the sound test you may need to construction independent internal plasterboard lining throughout the inner perimeter wall, this should isolate the lightweight blocks and ensure the flanking path is minimized.

If the onsite construction has gaps, cracks or holes it will conduct airborne sounds and can significantly reduce the sound insulation of a construction. For optimum sound insulation a construction must be airtight. Most small gaps can be sealed at the finishing stage using Gyproc jointing compounds. Small gaps or air paths around perimeter Gypframe framework can be sealed with sealant. At the base of the partition, gaps will occur which can be filled with acoustic mastic.

If you would like more information in regards to sound insulation testing and or acoustic design advice, then please call us now at info@airpressuretesting.net or call me (Darren) direct on 07775623464.

Sound Testing Rating Methods

Sound Testing Rating Methods

Sound tests are broken down into various sound testing rating methods. The sound insulation definition and terms are as follows:

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.

Acoustic_Design_Service

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 acoustician 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 for laboratory 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

This is a 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.

If you have a project that’s needs acoustic design advice or sound insulation testing, then please contact us at: info@aptsoundtesting.co.uk or phone me (Darren) directly on 07775623464.

The Two Types of Sound Insulation Test

The Two Types of Sound Insulation Test

There are two types of sound insulation testing, Airborne and Impact.

Airborne sound testing is undertaken to walls & floors. Firstly a controlled noise is generated by an amplifier and loudspeaker across a broad range of frequencies. The generated noise is very loud and is often in excess of 100dB. Initial measurements are taken using a class 1 sound level meter within the ‘source room’ followed by further measurements in the ‘receiver room’ on the other side of the wall or floor under investigation. The source room speaker position is then changed and the measurements repeated either side of the partition under test.

Sound_Insulation_Testing_Equipment

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 absorptive characteristics of the room.

The difference in the two airborne noise levels (for walls and floors), corrected for background and reverberation characteristics determines the airborne sound insulation performance of the wall, or floor. A greater airborne noise difference between the source room and the receiver room determines a higher airborne sound insulation performance.

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 wall tests will usually take between one and two 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, 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.

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.

 

A Successful Sound Insulation Test

A Successful Sound Insulation Test

There are many considerations to achieving a successful sound test on your development. The main areas that need to be addressed are the dividing wall and floor construction.

When dealing with walls you normally just need to worry about airborne sound; however with walls it’s both airborne and impact sound which can be far more difficult to deal with.

sound_transmission_through_floors

The usual noise problems associated with airborne sound transmission is TV noise, music and speech. This can be dealt with by applying ceiling treatments as well as mass and isolation to the building components. Impact sound (footfall) performance is increased by the used of resilience layers and isolation of components to prevent noise flanking through the partition.

Airborne Sound Testing

For airborne sound insulation testing Building Regulation Part E requires you achieve at least 45dB for new build properties and 43dB for conversion developments, this applies both to party walls and floors between properties. This level is the difference between the source level and the receiver level during sound testing. Impact Sound TestingThe measurement is corrected for several factors such as background noise, room characteristics and frequency weighting, giving the final sound insulation performance value of the tested partition. In this case the higher the number the better the sound insulation performance. The measurement is done by using a Class 1 Analyser and the associated equipment.

Impact Sound Insulation Testing

For impact sound insulation testing Building Regulation Part E requires you achieve at least 62dB for new build properties and 64dB for conversion developments. Impact insulation performance only applies to party floors and related to the effectiveness of the floor construction in absorbing shock such as footfall noise.Sound_Insulation_Testing_Equipment

Good Acoustic Design

To try and ensure you meet the standards stipulated within Building Regulations Part E, careful consideration should be shown to the acoustic design detailing from the start of the project. Tackling the acoustic design for both new build and conversion project requires two different construction techniques and acoustic design detailing. With new build properties you have a blank canvas in terms of the overall design whereas with conversions you usually need to work with the existing’ onsite’ construction which can be quite difficult.

We 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 which 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.
  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.

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

We have also started our new facebook page at: https://www.facebook.com/APT-Sound-Testing-1705040043131199/

Sound Testing to Comply with Lease Conditions

Sound Testing to Comply with Lease Conditions

Many people unknowingly fail to abide by the lease agreement as they may not know that there is usually a condition that states that they need to employ an acoustic company prior to making any changes to the floor of their apartment. The lease conditions often states that you need to undertake sound insulation testing prior to the commencement of works and upon completion of works.

In many cases their neighbour/s may complain that they can hear extra noise, this is often due to the fact that they may have changed the floor finish from carpet to wood. Unless extra acoustic design considerations are taken into account it usually results in an increase of extra airborne and impact noise being heard in unit below.

Sound_Testing_for_Lease_Agreements

Even if the floor assembly has been designed and constructed to provide adequate airborne isolation, impact noise can still be a major problem. If the finished floor surface had previously been carpet, the carpeting and underlay will normally provide a good degree of impact sound isolation. On the other hand, when the finished floor is floor is constructed in hardwood, stone or ceramic tile. Achieving good impact sound isolation requires much more attention.

If you think you may have a problem with sound in your dwelling and or you have encountered complaints from a neighbour due to modifications you have made to the floor partition then please contact us now. In all cases try be sure to describe the problem in as much detail as possible. Describe the nature of the sounds, when and where you or your neighbour can hear it. Is it impact noise or airborne noise or a combination of both? The more information you can provide us, the quicker we can try to determine the nature of the problem and subsequently find a solution.

In many cases, due to the complexity of acoustical and noise problems due to varying constructions, it is impossible to cover all problems in a short article such as this; however in our experience if we are employed from the beginning of a project, it usually results in compliance with Building Regulations Part E and /or compliance with your leasehold agreement, which may avert costly legal battles at the end of the project.

If you are about to make changes to your apartment, and you think you require acoustic design advice, then please contact us now at: info@aptsoundtesting.co.uk  or phone me directly on 07775623464.

 

Sound Testing for Compliance with Lease Conditions

Sound Testing for Compliance with Lease Conditions

If you own or manage an apartment it has a lease agreement that has conditions relating to the changing of the floor construction, then you may require Sound Testing for Compliance with Lease Conditions. We undertake many leaseholder sound tests throughout London and the South East and offer a ‘4 step acoustic package’  to satisfy your lease conditions comprising of the following:

  1. Sample Sound Testing of the existing construction. This offers an accurate overview of the acoustic performance of the existing floor partition/s prior to the commencement of construction works. It also enables us to offer a targeted acoustic design using the sound insulation performance of the existing construction.
  1. Acoustic design review – once we have the performance figures from the sample sound testing have been established, we can forward a design that should improve the performance of the existing floor partition – even if you are changing the floor from a carpet to engineered timber floor finish!
  1. Site Visit – This allows us to check that the installation team is installing the acoustic materials as per manufacturer’s guidelines.
  1. Final Precompletion Sound Testing in-line with Approved Document E. This provides an accurate overview of the acoustic performance of the upgraded partition/s, the results of which can be handed over to the relevant person for sign off.

In most cases complaints are usually raised from impact noise such as foot fall from hard bottomed shoes etc. this is accentuated when the unit above has changed their floor finish from carpet to wood.

Sound_Insulation_Testing_Equipment

If you think you may have a problem with sound in your dwelling and or you have encountered complaints from a neighbour due to modifications you have made to the floor partition then please contact us now we can provide our ‘3 step plan’ to satisfy your units lease conditions, then please contact us now at: info@aptsoundtesting.co.uk  or phone Darren directly on 07775623464.

Careful Acoustic Installation leads to Successful Sound Testing

Careful  Acoustic Installation leads to Successful Sound Testing

It is very important that acoustic installation details are closely followed to ensure that the onsite results are as close as possible to the laboratory target. It is pointless having good acoustic design detailing if this is not carefully followed on site.

Acoustic_Design_Service

The following list explains what should during the onsite construction process to achieve a successful onsite sound tests and Part E compliance:

  1. Ensure that the construction team is fully briefed of the acoustic details.
  2. Ensure that the manufactures installation booklet is on site at all times.
  3. Ensure that the Acoustic floor is fitted with staggered joints.
  4. If you are installing floating screed ensure all isolation layer joints are overlapped and taped.
  5. Ensure all the Acoustic floor is sealed watertight even around heating pipes.
  6. Do not nail or screw through an Acoustic Floor.
  7. Do not screws plaster board into joists, when using a Resilient Bar system.
  8. Ensure the insulation fills the whole width of void
  9. Pack around pipe work and double board with staggered joints.
  10. Ensure that the plasterboard on any walls is complete right down to within 5-10mm of the subfloor and seal all gaps.
  11. Ensure you use the isolation tape around the wall of each room.
  12. Ensure plasterboard is fitted with staggered layers and all joints sealed.
  13. If using Resilient Bars ensure that they are fitted as per manufacturer’s recommendations.
  14. Ensure all Fireplaces are blocked up with brick or a twin lined plasterboard system and filled with acoustic insulation.
  15. Ensure that any RSJ’s or supporting steel work is insulated and isolated from plasterboard.
  16. Ensure all waste pipe service runs are boxed in with insulation and plasterboard.
  17. Ensure all doors and windows are installed before the test is carried out, to stop noise transference.

We offer an acoustic design service which includes site visits to make sure the acoustic elements are being installed as per the manufacturer’s guidelines. If you are worried about passing your sound testing at the first attempt please don’t hesitate to contact us now at: info@aptsoundtesting.co.uk or call Darren Direct on 07775623464.