Sound resistance

Fyfestone Sound Resistance Picture of a buildingFyfestone Sound Resistance Picture of a gymnasiumFyfestone Sound Resistance Picture residential buildings

Fyfestone and Masterblock solutions for sound insulation are available for residential, school, hospital and commercial buildings.

 

For residential properties, Masterblock products can be used in Robust Detail separating walls and flanking walls, and also in constructions described under the guidance of Approved Document E (2003 Edition).

 

The control of sound is an essential part of any new building design.

 

The design parameters which must be considered are:

  • The control of noise emissions from within the building to the outside, e.g. factory noise
  • The control of external environmental noise emissions into the building, e.g. traffic, aircraft or equipment noise
  • To ensure that the correct acoustic climate exists within the building which is relevant to the building’s intended use

 

There are two regulatory documents that apply to sound. They are as follows:

 

In Scotland – Part H of the Building Standards (Scotland) – Resistance to the transmission of sound is applicable. The requirements of Part H only apply to walls and floors separating a dwelling from other parts of the same building in different occupation and from other adjoining buildings.

 

In England and Wales – Approved Document E of the Building Regulations – Resistance to the passage of sound applies. The overall aim is to improve the sound insulation between dwellings as well as between rooms in hotels, residential homes and hostels. The scope has also been extended to include reverberation in common parts of blocks of flats and acoustic conditions in schools which are now controlled under the Building

 

Regulations and guidance on meeting this requirement is given in Building Bulletin 93 – The Acoustic Design of Schools.

 

The fundamental differences between Part H (Scotland) and Part E (England and Wales) are as follows:

  • Part H (Scotland) does not have two sets of performance criteria for new-build or conversion projects
  • Part H (Scotland) has no 40dB requirement for internal partitions or mid-floors
  • Part H (Scotland) has no requirement for sound absorption in common areas of the building
  • Part H (Scotland) measures site performance by way of a DnTw measure only (unlike Part E England and Wales which also uses a Ctr – correction factor – particularly for bass sound).

 

The new Robust Details (RD) initiative is not available for use as a scheme with which to comply with the regulations in Scotland, although some of the constructions may be comparable to those which can be used for compliance

 

There are alternative routes by which to comply to Part H (Scotland):

  • Deemed to satisfy
    Use construction/provision details as given in Approved Document H that are deemed to satisfy the standards. Constructions listed which can be used to comply by this route are marked thus.
  • Similar constructions
    For example, if an identical block of dwellings has been built elsewhere, tested and shown to meet the performance standards a building warrant can be given on that evidence. Constructions listed which can be used to comply by this route are marked thus:

Deemed to satisfy

Fyfestone Sound Resistance Scottish flag

To comply using this method of compliance for Part H (Scotland) you must use construction/provision details as given in Approved Document H that are deemed to satisfy the standards. The constructions featured in this document that can be used in Scotland as a means of complying with Part H by this route are:

Separating Walls

  • E-WM-1 Masonry
  • Dense aggregate blockwork (wet plaster)
  • E-WM-3 Masonry
  • Dense aggregate blockwork (render and plasterboard)
  • Dense aggregate cavity masonry – drylined
  • Solid masonry (Wall Type 1)
  • Dense aggregate cavity masonry (all type 2.1)

Similar constructions

Fyfestone Sound Resistance Scottish flag 2

To comply using this method of compliance for Part H (Scotland) requires evidence based on an identical block of dwellings that has been built elsewhere, tested and shown to meet the performance standards – a building warrant can then be given based on that evidence.

 

Those constructions featured in this document that can be used in Scotland as a means of complying with Part H by this route are:

Separating Walls

  • E-WM-2 Masonry
  • Lightweight aggregate blockwork (wet plaster)
  • E-WM-4 Masonry
  • Lightweight aggregate blockwork (render and plasterboard)
  • Lightweight aggregate cavity masonry (wall type 2.2)
  • Masonry between independent panels (wall type 3.1)

Performance standards

Performance standards to be achieved if the ‘Similar constructions’ method is to be used as a means of complying with Part H (Scotland):

AIRBORNE SOUND* WALLS (mean value dB) WALLS (individual value dB) FLOORS (mean value dB) FLOORS (individual value dB) IMPACT SOUND* WALLS (mean value dB) WALLS (individual value dB) FLOORS (mean value dB) FLOORS (individual value dB)
53 49 52 48 * Minimum values of weighted standardised level difference (DnTw) as defined in BS EN ISO 717–1:1997. - 61 - 65 * Minimum values of weighted standardised impact sound pressure level (LnTw) as defined in BS EN ISO 717-2:1997.

Summary of the building regulations –

Part E requirements

Part E of the Building Regulations applies to houses, flats, rooms for residential purposes* and schools.

Regulation E1

PROTECTION AGAINST SOUND FROM OTHER PARTS OF THE BUILDING AND ADJOINING BUILDINGS

 

Dwelling houses, flats and rooms for residential purposes shall be designed and constructed in such a way that they provide reasonable resistance to sound from other parts of the same building and from adjoining buildings.

 

In simple terms, this means that separating walls/floors and the associated flanking walls/floors must be built so that they achieve a certain level of sound insulation when they are measured. Approved Document E gives guidance on the numerical values of airborne and impact sound insulation that should be achieved. It also describes how testing on site (“pre completion testing”) should be carried out at the expense of the builder, to demonstrate that the construction has been designed correctly and has been built to a suitable standard of workmanship. The test is used to confirm that the test is used to confirm that the construction achieves the specified minimum level of sound insulation described in Approved Document E.

 

As an alternative to pre completion testing in a new houses and flats, Robust Details Ltd publish separating wall and floor constructions, each of which are described as a Robust Detail (RD). Robust Details are separating wall or floor constructions that have been tested to demonstrate that they are capable of providing consistently good performance. In many cases, the use of an RD eliminates the need for pre completion testing.

Regulation E2

Protection against sound within a dwelling house etc.

Dwelling houses, flats and rooms for residential purposes shall be designed and constructed in such a way that:

 

Internal walls between a bedroom or a room containing a water closet, and other rooms provide reasonable resistance to sound

internal floors provide reasonable resistance to sun

 

In simple terms, this means that certain internal walls and floors in residential properties must achieve a certain level of airborne sound insulation.

 

Approved Document E gives guidance that this level of airborne sound insulation should be at least 40dB Rw when the internal wall or floor is measured in a laboratory. There is no need to measure the performance of these internal walls and floors by testing on site.

Regulation E3

Reverberation in the common internal parts of buildings containing flats or rooms for residential purposes

The common internal parts of buildings which contain flats or rooms for residential purposes shall be designed and constructed in such a way as to prevent more reverberation around the common parts than is reasonable.

 

In simple terms, this means that the common areas of flats and residential rooms (corridors, hallways, stairwells and entrance halls) will need additional absorptive material. Approved Document E describes how to determine the amount and type of absorptive material that is needed.

Regulation E4

Acoustic conditions in schools

Guidance on school acoustics is contained in Building Bulletin 93, published by DfES.

Part E

Performance standards

Achieving the required sound insulation performance depends upon the correct design, careful detailing and good workmanship. There are two routes to show that the sound insulation of separating walls/floors complies with Part E of the Building Regulations: through the use of pre completion testing or Robust Details.

Pre completion testing

A significant change in the new Part E is the introduction of pre completion testing on site to demonstrate compliance with Requirement E1.

 

Sound insulation tests are carried out once the rooms either side of a separating wall or floor are essentially complete, except for decoration.

Guidance on pre completion testing is contained in Section 1 of Approved Document E.

 

Testing should be carried out for:

  • Purpose-built dwelling houses and flats
  • Dwelling houses and flats formed by material change of use
  • Purpose-built rooms for residential purposes
  • Rooms for residential purposes formed by material change of use

 

For each development, Building Control Bodies identify the properties that should be tested. Full details of pre completion testing are explained in Section 1 of Approved Document E.

Robust details

For new houses and flats, Robust Details have been developed by the House Builders Federation, and these can be used to demonstrate compliance with Part E of the Building Regulations as an alternative to pre completion testing.

 

Many of the blocks that are described in Robust Details for separating walls or flanking walls match the technical specifications of Fyfestone and Masterblock products.

Approved document E

Performance standards

The sound insulation performance standards for dwelling houses and flats, and for rooms for residential purposes, are shown below.

Dwelling houses and flats

Performance standards for separating walls, separating floors and stairs that have a separating function

 

PURPOSE BUILT DWELLING HOUSES AND FLATS WALLS (airborne sound insulation DnT,w + Ctr dB (minimum values)

45

WALLS (impact sound insulation L’nT,wdB (minimum values)

-

FLOORS AND STAIRS (airborne sound insulation DnT,w + Ctr dB (minimum values)

45

FLOORS AND STAIRS (impact sound insulation L’nT,wdB (minimum values)

62

DWELLING -HOUSES AND FLATS FORMED BY MATERIAL CHANGE OF USE WALLS (airborne sound insulation DnT,w + Ctr dB (minimum values)

43

WALLS (impact sound insulation L’nT,wdB (minimum values)

-

FLOORS AND STAIRS (airborne sound insulation DnT,w + Ctr dB (minimum values)

43

FLOORS AND STAIRS (impact sound insulation L’nT,wdB (minimum values)

64

ROOMS FOR RESIDENTIAL PURPOSES

Performance standards for separating walls, separating floors and stairs that have a separating function

 

PURPOSE-BUILT ROOMS FOR RESIDENTIAL PURPOSES WALLS (airbourne sound insulation DnT,w + Ctr dB (minimum values)

43

WALLS (impact sound insulation L’nT,wdB (minimum values)

-

FLOORS AND STAIRS (airbourne sound insulation DnT,w + Ctr dB (minimum values)

45

FLOORS AND STAIRS (impact sound insulation L’nT,wdB (minimum values)

62

ROOMS FOR RESIDENTIAL PURPOSES FORMED BY MATERIAL CHANGE OF USE WALLS (airborne sound insulation DnT,w + Ctr dB (minimum values)

43

WALLS (impact sound insulation L’nT,wdB (minimum values)

-

FLOORS AND STAIRS (airborne sound insulation DnT,w + Ctr dB (minimum values)

43

FLOORS AND STAIRS (impact sound insulation L’nT,wdB (minimum values)

64

Planning

Acoustic design generally involves introducing measures to:
Control the level of sound in particular parts of a building

Limit the transmission of unwanted noise

These objectives can be obtained through careful consideration of building layout and the specification of building fabric with the appropriate acoustic performance. The latter is affected by two main criteria, sound insulation and sound absorption. Sound insulation is usually the main consideration but sound absorption is the key consideration where the control of reflected sound is essential, for example in theatres or concert halls.

Concrete blockwork has long been recognised to combine good acoustic performance with structural, thermal and fire resisting properties. The use of Fyfestone and Masterblock products enables the acoustic requirements of many situations to be met in a practical and cost effective manner.

 

As the amount of sound transmitted through a wall is related to its area, consider minimising the shared wall area between critical rooms by adopting alternative shapes and orientations. Introducing steps and/or staggers can help reduce the shared wall area and improve the sound insulation.

Room layout

Where possible, arrange the internal layout of a building to separate noisy and quiet areas. The distance between those areas can be increased by forming ‘buffer zones’ from rooms such as kitchens, store rooms and corridors, which do not have critical levels of sound transmission.

 

In dwelling houses, flats and rooms for residential purposes it is beneficial to avoid placing bedrooms in one dwelling directly opposite, underneath or above living rooms, kitchens and bathrooms in the adjacent dwelling.

Solutions for schools

To satisfy Requirement E4 on the acoustic conditions in schools, DfES Building Bulletin 93 ‘The Acoustic Design of Schools’ (http://www.teachernet.gov.uk/acoustics) contains the performance standards and guidance on achieving those performance standards.

 

Because of the complexity of school design, BB93 says that in all but the simplest cases, it is advisable to appoint a suitably qualified acoustic consultant who would normally be a corporate member of The Institute of Acoustics (www.ioa.org.uk).

 

Fyfestone and Masterblock offer a variety of masonry solutions for educational buildings to satisfy the performance levels required. Unlike the performance standards for dwellings, the Ctr spectrum adaptation value is not used to define sound insulation in schools.

Attention to detail

The full potential of a construction to provide sound insulation will only be realised if the construction is correctly detailed and assembled to a good standard of workmanship.

Attention should be paid to the following:

  • All mortar joints should be well filled to avoid air paths
  • Joints between separating walls and other parts of the construction should be sealed to avoid airpaths
  • Attention should be paid to the type and spacing of wall ties in masonry cavity walls.
  • Butterfly ties (or Tie type A as described in Approved Document E) should be used to ensure that the sound insulation of a masonry cavity wall is not compromised by ties that are dynamically stiff.
  • Ensure that masonry cavity walls are not built off a continuous solid concrete floor slab as this will provide a ‘sound bridge’ for vibration to be transmitted from one wall leaf to the other
  • Where a timber floor construction is used as an intermediate floor, joists spanning perpendicular to separating walls should preferably be fixed with joist hangers and should not be carried through the sound resisting wall
  • The minimum thickness of a separating wall required for sound insulation should always be maintained, particularly where chases, recesses, chimney flues, electrical sockets etc. are to be built into a wall
  • The inner leaf of cavity external walls should be of sufficient mass to prevent flanking transmission. See the specific guidance in Approved Document E or Robust Materials
  • Ensure that any external cavity wall is stopped with a flexible closer at the junction with the separating wall, unless the cavity is fully filled

  • For further technical advice on the use of Fyfestone, please contact the Fyfestone Technical Department on 01285 646800.

     

  • * Room for residential purposes means a room, or suite of rooms, which is not a dwelling house or flat and which is used by one or more persons to live and sleep in, including rooms in hotels, hostels, boarding houses, halls of residence and residential homes but not including rooms in hospitals, or other similar establishments used for patient accommodation.