Why Good Acoustic Design is Important

Why Good Acoustic Design is Important

The importance of good acoustic design and construction should never be under-estimated. If a project fails the sound insulation testing at the precompletion stage, it may need costly remedial work and may delay the buildings handover to the client.

We provide an acoustic design service to Architects, Property Developers and Building Contractors. We specialise in helping small developers pass their sound testing to achieve Part E compliance on all types of projects such as new build dwellings, apartment blocks, and conversion projects such as the changing of offices into residential dwellings.

Many of our clients have previously conveyed negative feedback that larger acoustic consultancies don’t always understand small builder requirements and subsequently often produce complicated acoustic design detailing that are both difficult (in terms of build-ability) and very costly to undertake. We try to provide acoustic solutions that are cost effective and easy to construct, saving our clients time and money.

In our experience by simply constructing a robust separating wall or floor may not-itself provide sufficient sound insulation to pass Building Regulations Part E, as the junctions of each separating wall and/or floor with other parts of the building are equally as important and require careful consideration to prevent noise flanking etc.  Noise flanking transmission can occur via construction components such as:

  • Dividing Ceiling Partitions – Above and Through the Ceiling Space (where an adequate acoustic break has not been carried on through the ceiling void)
  • Dividing Floor Partitions – 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)
  • Shared Structural Building Components – Floor Boards, Floor Joists, Continuous Drywall Partitions, Continuous Concrete Floors, and Cement Block Walls.
  • 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)
  • 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 Windows (if they are no double glazed or have secondary glazing as a minimum)
  • Fixtures & Outlets – Light Switches, Telephone Outlets, and Recessed Lighting Fixtures (if penetrations have been cut back to back with the opposite dwelling under test)
  • Structural Joints – Perimeter Joints at Wall & Floor, Through Wall & Ceiling Junctures (these should be filled with acoustic mastic)
  • Around the End of the Partition Through the Adjacent Wall (acoustic mastic should be used to seal this junction)

In our experience, flanking sound transmission often occurs through lightweight inner walls and is often the dominant pathway between adjoining dwellings. When converting existing buildings in to residential dwellings such as offices conversions and existing wall and floor construction should be carefully considered during the final design, as extra wall/floor linings may be required to upgrade the existing construction to prevent excess noise transference and prevent sound test failure at the end of the project.

We offer an easy to follow turnkey solution for to fulfil our clients acoustic requirements. We can usually provide considerable cost and efficiency benefits for all our clients’ new build and conversion projects.

If you would like more information in regards to our acoustic design and sound insulation testing service please contact us now.

 

The Four Elements to Good Sound Proofing

The Four Elements to Good Sound Proofing

Customers often ask how they can improve soundproofing on their developments. The first thing to understand is the basic of soundproofing design and construction. If you understand the basics, you’ll have a more educated view point in regards to the way sound and vibration behaves within your new dwellings. Basically, we want to stop sound and vibration through the walls and floors of your development. In general, we are trying to stop vibrations from getting to “your” side of the wall or ceiling as this may result in a sound test failure when you undertake your precompletion testing.

The plate below shows a typical wall and noise problems associated with it. With this type of construction noise transference is a big problem. If there is even moderate levels of noise on one side of the wall the chances are you will hear it.

Coupled Wall Construction 

If you look at the red arrows in the above diagram it clearly shows how sound is conducted from one side of the wall to the other. As the wall elements are firmly fixed against each other, i.e. the plasterboard is rigidly connected to the timber thus the noise and vibration conducts straight through the whole wall construction.

If you look at the blue waves this indicates airborne transmission. The plasterboard is vibrating back and forth which produces a sound wave in the wall cavity. This, in turn, vibrates the plasterboard on the opposite side of the wall so the whole construction acts like a huge diaphragm; or like a large speaker with both sides of the wall vibrating in unison.

To reduce noise transference you need to undertake to design and construct taking into account the four following items:

  1. Decoupling of materials.
  2. Noise absorption
  3. Adding Mass
  4. Noise Damping

If you would like more information in regards to acoustic design or sound insulation testing on your project please contact us now at: info@aptsoundtesting.co.uk or call me direct on 07775623464. For a complete list of our services please visit our website at: www.aptsoundtesting.co.uk

Our Four Step Acoustic Design Package

Our Four Step Acoustic Design Package

To try and help our clients pass their sound insulation testing at the first attempt, we offer the following 4 step acoustic design package:

  1. 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.
  2. 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.
  3. Acoustic Design Reviews – a full design review of the proposed developments party walls and floors.
  4. Precompletion Sound Testing – to satisfy Approved Document E.

We provide the site team with on-going design support service, so you will have direct contact with the allocated acoustic engineer from the start of the process through to the successful completion of the project.

One of the most important services is the going site survey visits which allow our clients to feel confident about the outcome of testing at the end of the build. The site visits let us check that the installation teams are installing the acoustic materials as per manufacturers avoiding crucial onsite mistakes. You can often have a compliant design which still fails due to poor workmanship; the site survey visits negate the risk of sound test failure.

We will evaluate the construction methods and materials specified to ensure that they are capable of meeting the acoustic requirements of Approved document E. The typical areas we check are:

  1. There are no flanking points, where isolated partitions are wrongly mechanically fixed together to caused noise bridging.
  2. The walls and floors design are acoustically robust, to comply with Building Regulations Part E.
  3. The acoustic treatments for Soil Pipes, Stair Cases Steel Beams etc. to ensure they are acoustically fit for purpose, as these are some of the areas that get usually missed.
  4. Acoustic floor treatments are compatible with the proposed floor finishes i.e. Carpets, Laminates, Floor Tiles and under floor heating systems.

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 also undertake UKAS accredited sound testing providing a ‘one stop’ solution for all your acoustic requirements.

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 and 07775623464 or visit our website at: www.aptsoundtesting.co.uk

What is Sound Testing?

What is Sound Testing?

Sound testing is a requirement of Approved Document E to assess the sound insulation performance of party walls and floors between dwellings. Sound testing is usually required once the property is nearing completion and is carried out to determine if the minimum Building Regulation Part E for sound insulation has been met. The contractor is responsible for arranging the sound testing to demonstrate compliance to Building Control that the dividing partitions have achieved compliance with Approved Document E for sound insulation. The aforementioned procedure is more commonly referred to as Approved Document E (ADE) sound testing or pre-completion testing (PCT).

Sound Testing in London 

Approved Document E – ‘Resistance to the passage of sound’ came into force on July 1st 2003 and provided the minimum sound insulation values for new and converted dwellings.  This includes the following building types: flats, houses, student accommodation, care homes, hotels and schools. Approved Document E is a government-issued document which provides guidance for building contractors, architects and developers involved in the design and conversion of buildings for residential purposes. Approved Document E explains the sound insulation requirement for each type of building and provides acoustic advice and details about building procedures and materials that may affect the sound test results.

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. For conversion properties a slightly easier target of 43dB for airborne wall and floors and 64dB for Impact Sound Testing is required.

We can help you to achieve this more robust design criterion. We can also help if your building fails the sound insulation testing by offering a targeted acoustic design solution saving time and potential costs.

The Pathway to Good Sound Proofing

The Pathway to Good Sound Proofing

Clients often asked us how they can improve the soundproofing on their developments to pass their sound insulation test. The first thing to understand is the basic of soundproofing design and construction. If you understand the basics, you’ll have a more educated view point in regards to the way sound and vibration behaves within your new dwellings. Basically, we want to stop sound and vibration through the walls and floors of your development. In general, we are trying to stop vibrations from getting to “your” side of the wall or ceiling as this may result in a sound test failure when you undertake your precompletion testing.

The plate below shows a typical wall and noise problems associated with it. With this type of construction noise transference is a big problem. If there is even moderate levels of noise on one side of the wall the chances are you will hear it.

Noise Transference 

If you look at the red arrows in the above diagram it clearly shows how sound is conducted from one side of the wall to the other. As the wall elements are firmly fixed against each other, i.e. the plasterboard is rigidly connected to the timber thus the noise and vibration conducts straight through the whole wall construction.

If you look at the blue waves this indicates airborne transmission. The plasterboard is vibrating back and forth which produces a sound wave in the wall cavity. This, in turn, vibrates the plasterboard on the opposite side of the wall so the whole construction acts like a huge diaphragm; or like a large speaker with both sides of the wall vibrating in unison.

To reduce noise transference you need to undertake to design and construct taking into account the four following items:

  1. Decoupling of materials.
  2. Noise absorption
  3. Adding Mass
  4. Noise Damping

We can advise on all types of acoustic design, whether it’s accomplished during initial construction or during a refurbishment/renovation project. If you would like more information in regards to our acoustic design and sound testing services, please contact us now.