Month: June 2021

How to Pass Sound Testing for Party Walls

How to Pass Sound Testing for Party Walls

Tips on How to Pass Sound Testing for Party Walls

There are many reasons why party walls fail the pre-completion sound testing. To try and help our customers we have written this article, which should help you achieve a sound test pass at the first attempt and avoid expensive remedial works.  

What is airborne sound?

Airborne noise/sound is defined as any sound that is transmitted via the air, like speech or music. Sound waves are picked up and carried by air until they hit something solid, like a wall, floor, or ceiling. The collision sends vibrations through the wall and into the space beyond it. This is why you are able to hear music or shouting from neighbours as if it were inside your home; the sound waves created are carried by air until they reach your walls and vibrate through them which can be a real pain.

Under Approved Document E you are only required to undertake airborne sound testing for party walls. For floor partitions you are required to carry out both airborne and impact sound testing. 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.

How to Pass Sound Testing for Party Walls

The main acoustic design considerations for party walls in flats

To improve the chance of a successful sound test and reduce the chance of noise flanking you will need to ensure that you allow for the following five acoustic design considerations, when upgrading an existing floors and walls in flats they are:

  • Mass
  • Isolation
  • Absorption
  • Resilience
  • Stiffness

Items to action prior to the undertaking of sound testing through Walls.

  1. The whole building envelope and internal walls and floors should be fully completed.
  2. All service boxings should be in place – usually located around kitchens/ bathrooms etc.
  3. All electrical fittings must be completely in-place, and fully functional. Poor electrical installation can lead to excess noise.
  4. Electrical sockets should never be placed back-to-back in walls as this can cause an acoustic weak point.
  5. If kitchens are constructed on party walls it is a good idea to introduce a service liner so excess services penetrations holes are not cut through the party wall.
  6. All internal and external doors and windows should be installed and closing properly.
  7. No carpets or laminated flooring should be fitted at the time of the testing. These materials can affect the movement of noise, and as a result could impact on whether a building passes the sound check test.
  8. The building skirting board should not touch the floating floor – an acoustic flanking strip should be installed.
  9. All gaps in walls and floors should be sealed. Noise can leak out through any gaps, affecting the movement of sound and impacting on the space’s performance.
  10. All noisy works should be stopped for the duration of the testing as this can have a negative effect on the sound test results.
How to Pass Sound Testing for Party Walls

A simple acoustic upgrade for existing party walls

If you have an existing party wall that is being retained in your conversion project, one quick and simple way to improve the acoustic performance of existing dividing wall partition can be achieved by installing a 70mm met-sec partition in front of the existing wall – it is usually best to install this in the largest room. Leave approx. 25mm gap between the back of the met-sec and the wall. Then install 50mm acoustic wool with a minimum mass of 45kg/m3 to the inside of the met-sec. This can then be fished by adding two layers of 15mm soundboard to the outside of the met-sec frame – ensure all boards are properly lapped and the perimeter joints are filled with acoustic mastic.

How APT Sound Testing can help with your acoustic requirements 

It can be very time-consuming trying to identify the cause of a failed sound test. Therefore, it is always best to hire an experienced consultant. APTs acoustic consultants have years of experience and will advise you on the best course of action to rectify any problems with the acoustic design on your project. We are also a UKAS accredited company, so you can be sure of a friendly and professional service providing a ‘one stop’ solution for all your acoustic requirements.

APT can advise on all types of acoustic design to help you pass your sound testing to party walls and floors in flats, whether it is accomplished during initial construction or during a refurbishment or renovation project. Whatever the problem we can usually find an acoustic solution that will help you achieve Building Regulation compliance, reducing the risk of costly remedial works to your project prior to handover.

If you require sound insulation to party walls or floors, or you need an acoustic design review on your development, please contact us now or visit our acoustic design page.

For further advice on acoustic design and sound testing services please contact our expert acoustic consultants today on 01525 303905 or email us at for friendly advice about building party walls and floors and/or sound insulation testing on your construction project.

Frequently Asked Questions for Room Integrity Testing

Frequently Asked Questions for Room Integrity Testing

Frequently Asked Questions for Room Integrity Testing

Server rooms and data centres that have gaseous fire extinguishing systems are required to be tested on an annual basis; however, not all clients are aware that they need to undertake a room integrity test, let alone what is involved. It’s also worth noting that if your protected enclosure suffers fire damage, it may not be covered by the building’s insurance if you don’t have up-to-date Fire Integrity Certification.

Room Integrity Testing

For your fire suppression system to work properly, the room must have sufficient integrity to retain an extinguishing concentration for a specified period after discharge – usually 10 minutes. If the enclosure cannot adequately hold the extinguishment the fire may reignite causing further damage to protected enclosure and critical assets.  

To try and explain what is involved in a room integrity test, we have written the following question and answers article:

Q – Why do I need a room integrity test?

A – The test is a requirement of the British Standard for gaseous fire extinguishing systems – BS EN:ISO 14520. Most fire insurers will require evidence that the test has been conducted and the result is satisfactory.

Q – How quickly can a room integrity test be arranged?

A – We can usually undertake an integrity test within a few days of our client’s enquiry; however, in the case of an emergency we do offer a 24-hour service.

Q – How do I prepare my protected enclosure for the integrity test?

A – We send out an informative checklist with all our quotations, to help clients prepare for the integrity test.

Q – How long does it take to carry out a room Integrity test?

A The room integrity test usually between 1 and 2 hours for a single enclosure.

Q – Will the enclosure integrity test set off alarms?

No, the enclosure test is completely independent of the detection system; however the room should be isolated and the system turned to manual in-line with our room integrity checklist.

Q – Is the room integrity test disruptive?

A – No, it is only necessary to stop access to the room for 10-15 minutes. Personnel – such as IT staff can continue to work in the room. The enclosure test can be paused if immediate access becomes required.

Q – Does equipment such as servers need to be switched off during the room integrity test?

A – No, the servers can carry on running throughout the room integrity test.

Q – Does air conditioning need to be switched off during the enclosure integrity test?

A – Recirculation (chiller) units may continue to run. Air supply/extract ducts passing into the enclosure will need have the fire dampers closed and/or be temporarily sealed throughout the duration of the test.

Q – Will I get a certificate if I pass the room integrity test?

A – Yes, the certificate will be issued within a few days. This should be retained for possible inspection by the authorities/insurers. We will verbally let you know if the enclosure test has passed or failed whilst on site.

Q – What happens if the room fails the room integrity test?

A – A low impact smoke test can be undertaken along with a corresponding report to identify the leakage paths for remedial sealing.  Once the remedial works have been undertaken a retest must be conducted to confirm the adequacy of the retention time along with the corresponding pass certification.

Q – Can remedial sealing be done at the time of the enclosure test if its initially failed?

A – Yes, provided the leakage can be swiftly remedially, or temporarily, sealed.

Q – Does APT undertake remedial sealing?

Yes, we can undertake the remedial sealing if so required, or the client can arrange the works themselves. 

Q – How often should the room integrity test be done?

A – The relevant British Standard (BS EN:ISO 14520) specifies that the test should be conducted within a 12-month period and/or if any works have been undertaken to the enclosure envelope i.e., new service penetrations are made to the walls, floors, or ceilings.

Q – Is there any corresponding standards for room integrity testing.

A – Yes, the following standard apply to room integrity testing: ISO 14520, NFPA 2001 and ISO 15004

Why use us for your room integrity test?

We offer a friendly and cost-effective one stop solution for all your integrity test requirements. Using the very latest blower door technology, we provide thorough retention reports as well as informative assessments concerning highlighting areas of leakage, advice and recommendations. We even offer a remedial sealing service should it be required. 

If you would like more information on our server room integrity testing, please visit us at or visit our Room Integrity Page.

Sound Insulation Testing Terminology

Sound Insulation Testing Terminology

Sound Insulation Testing Terminology
Developers and landlords may need to improve sound insulation over a wide range of houses and flats. This may be due to the fact they have just built a new development that requires sound insulation testing under Part E or as part of a general refurbishment programme, i.e. changing houses into flats.

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 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.

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.

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.

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

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.

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 skirtings.

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.

This is a strategy to limit the number and type of rigid connections between elements of construction.

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.

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).

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.

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.

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. If you have a project that requires acoustic design and/or sound insulation 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 on 01525 303905 or visit our website at:    

The Secret to Successful Sound Testing

The Secret to Successful Sound Testing

The Secret to Successful Sound Testing
There are many considerations to achieving successful sound testing 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.

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.

The Secret to Successful Sound Testing

Successful Sound Testing
For airborne sound 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. Therefore, if the source level in one flat is 110dB and the receiver level in the neighbouring flat is 55dB, the level difference (or sound reduction performance) is 55dB.

The 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 Testing
For impact sound 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. The measurement is done by using a Norsonic tapping machine (as shown below). The machine has 5 weights which tapping in regular succession on the tested floor which emulates footfall noise. The noise levels are taken in the receiving room below, which are then measured and averaged for different tapper positions, which then gives the sound reduction rating of the floor. In this case the lower the figure, the better the performance.

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 stat of the project. offset. 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:

a.            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.

b.            Acoustic Design Review – a full design review of the proposed developments party walls and floors.

c.             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.

d.            Final Precompletion Sound Testing in compliance with Building Regulations Part E.

Useful Acoustic Design Considerations

a.            Avoid the use of lightweight blocks in the inner envelope construction and/or stairwell construction etc. as sound will travel both vertically and horizontally from dwelling to dwelling.

b.            The use of resilient suspended ceilings will help improve the performance of the floor partition.

c.             Ensure all support steels/timbers are carefully boxed out where they travel from flat to flat vertically and horizontally.

d.            Use a high quality resilient acoustic membrane on top of the floor to improve the impact performance of a floor.

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.

In our experience the main 5 considerations when designing for separating walls and floors between dwellings are: If used together or in various combinations they will improve sound insulation properties over a wide range of frequencies. The main factors are:

a.            Mass

b.            Isolation

c.             Absorption

d.            Resilience

e.            Stiffness

If used together or in various combinations they will improve sound insulation properties over a wide range of frequencies and should achieve compliance with Building Regulations Part E.

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‘4 step’ acoustic package.

If you have a project that needs acoustic design advice or sound insulation testing, then please visit the APT Sound Testing website or phone us directly on 07775 623464.