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Part G Application and Interpretation
Regulation 48NI-wide·Technical Booklet G Resistance to the Passage of Sound
48.—(1) Regulation 50 shall not apply to— (a) an internal wall that contains a door; (b) an internal wall that separates an en-suite toilet from the associated bedroom; or (c) existing walls and floor
dwellingflatssoundnon-domesticSound insulation between domestic and non-domestic spaces
0.20NI-wide·Technical Booklet G Resistance to the Passage of Sound
The performance standards set out in Tables 1a and 1b are appropriate for walls, floors and stairs that separate spaces used for normal domestic purposes. Specialist advice may be needed to establish
dwellingsoundnon-domesticDepartment View on Regulation 51 - Sound Absorption Measures
0.23NI-wide·Technical Booklet G Resistance to the Passage of Sound
It is the view of the Department that the requirements of regulation 51 will be met by the use of sound absorption measures described in Section 7 of this Technical Booklet, or other measures of simil
soundnon-domesticDefinitions
1.1NI-wide·Technical Booklet G Resistance to the Passage of Sound
In this Technical Booklet the following definitions apply – Absorption – conversion of sound energy to heat, often by the use of a porous material. Absorption coefficient – a quantity characterising t
sounddwellingnon-domesticPlasterboard linings installation
2.16NI-wide·Technical Booklet G Resistance to the Passage of Sound
Plasterboard linings should be fixed according to manufacturer's instructions.
soundnon-domesticdwellingTie type B for external masonry cavity walls
2.20NI-wide·Technical Booklet G Resistance to the Passage of Sound
Connect the leaves of a cavity masonry wall only where necessary by wire type (double-triangle) ties as described in BS EN 845-1 and spaced as required for structural purposes, see BS 5628-3 which lim
soundstructuralexternal-spacenon-domesticdwellingSolid Masonry Wall Type 1 - Sound Resistance Principle
2.29NI-wide·Technical Booklet G Resistance to the Passage of Sound
The resistance to airborne sound depends mainly on the mass per unit area of the wall.
soundnon-domesticfire-safetySolid Masonry Wall Type 1 - Construction Types
2.30-2.31NI-wide·Technical Booklet G Resistance to the Passage of Sound
Three wall type 1 constructions (types 1.1, 1.2, and 1.3) are described in this guidance. Details of how junctions should be made to limit flanking transmission are also described in this guidance.
soundnon-domesticfire-safetySolid Masonry Wall Type 1 - Construction Requirements (Do's)
2.32(a-g)NI-wide·Technical Booklet G Resistance to the Passage of Sound
Do (a) Do fill and seal all masonry joints with mortar. (b) Do lay bricks frog up to achieve the required mass per unit area and avoid air paths. (c) Do use bricks/blocks that extend to the full thick
soundnon-domesticfire-safetySolid Masonry Wall Type 1 - Construction Restrictions (Do Not's)
2.32(h-j)NI-wide·Technical Booklet G Resistance to the Passage of Sound
Do not (h) Do not try and convert a cavity separating wall to a type 1 (solid masonry) separating wall by inserting mortar or concrete into the cavity between the two leaves. (i) Do not use deep socke
soundnon-domesticfire-safetyWall type 1.1 - Dense aggregate concrete block with plaster
2.33NI-wide·Technical Booklet G Resistance to the Passage of Sound
Dense aggregate concrete block, plaster on both room faces (see Diagram 2.2) – minimum mass per unit area including plaster 415 kg/m²; 13 mm plaster on both room faces; use blocks that are laid flat t
soundnon-domesticdwellingWall type 1.2 - Dense aggregate concrete cast in-situ with plaster
2.34NI-wide·Technical Booklet G Resistance to the Passage of Sound
Dense aggregate concrete cast in-situ, plaster on both room faces (see Diagram 2.3) – minimum mass per unit area including plaster 415 kg/m²; plaster on both room faces. The required mass per unit are
soundnon-domesticdwellingWall type 1.3 - Brick with plaster on both room faces
2.35NI-wide·Technical Booklet G Resistance to the Passage of Sound
Brick, plaster on both room faces (see Diagram 2.4) – minimum mass per unit area including plaster 375 kg/m2; 13 mm plaster on both room faces; bricks to be laid frog up, coursed with headers.
soundnon-domesticExternal cavity wall - cavity closure requirement
2.40NI-wide·Technical Booklet G Resistance to the Passage of Sound
Where the external wall is a cavity wall – (a) the outer leaf of the wall may be of any construction; and (b) the cavity should be closed with a cavity stop (see Diagram 2.9).
non-domesticdwellingsoundexternal-spaceExternal cavity wall with timber frame inner leaf - construction requirements
2.41NI-wide·Technical Booklet G Resistance to the Passage of Sound
Where the inner leaf of an external cavity wall is of framed construction, the framed inner leaf should – (a) abut the separating wall; and (b) be tied to it with ties at not more than 300 mm centres
non-domesticdwellingsoundExternal solid masonry wall junctions
2.42NI-wide·Technical Booklet G Resistance to the Passage of Sound
Seek specialist advice.
non-domesticdwellingsoundInternal framed walls - no restrictions
2.43NI-wide·Technical Booklet G Resistance to the Passage of Sound
There are no restrictions on internal framed walls meeting a type 1 separating wall.
non-domesticdwellingsoundInternal masonry walls - mass requirement
2.44NI-wide·Technical Booklet G Resistance to the Passage of Sound
Internal masonry walls that abut a type 1 separating wall should have a mass per unit area of at least 120 kg/m² excluding finish.
non-domesticdwellingsoundSealing lightweight aggregate blocks above ceiling level
2.56NI-wide·Technical Booklet G Resistance to the Passage of Sound
If lightweight aggregate blocks of density less than 1200 kg/m3 are used above ceiling level, then one side should be sealed with cement paint or plaster skim.
soundnon-domesticdwellingsCavity Masonry Separating Walls - Sound Resistance Principles
2.59NI-wide·Technical Booklet G Resistance to the Passage of Sound
The resistance to airborne sound depends on the mass per unit area of the leaves and on the degree of isolation achieved. The isolation is affected by connections (such as wall ties and foundations) b
non-domesticflatssoundseparating-wallParty Wall Thermal Bypass and Building Regulations Compliance
2.59NI-wide·Technical Booklet G Resistance to the Passage of Sound
Air movement in a cavity masonry separating wall can be a source of significant heat loss. This is known as the party wall thermal bypass and is addressed by Part F of the Building Regulations. Any me
non-domesticflatssoundenergyseparating-wallCavity Masonry Wall Type 2 Constructions
2.60, 2.61NI-wide·Technical Booklet G Resistance to the Passage of Sound
Four wall type 2 constructions (types 2.1, 2.2, 2.3 and 2.4) are described in this guidance. Two of these wall constructions (types 2.3 and 2.4) are only suitable when a step in elevation and/or a sta
non-domesticflatssoundseparating-wallJunction Details for Flanking Transmission Control
2.62NI-wide·Technical Booklet G Resistance to the Passage of Sound
Details of how junctions should be made to limit flanking transmission are also described in this guidance.
non-domesticflatssoundseparating-wallBest Practice Measures for Cavity Masonry Separating Walls
2.63NI-wide·Technical Booklet G Resistance to the Passage of Sound
Points to watch – Do (a) Do fill and seal all masonry joints with mortar. (b) Do keep the cavity leaves separate below ground floor level. (c) Do ensure that any external cavity wall is stopped with a
non-domesticflatssoundseparating-wallProhibited Practices for Cavity Masonry Separating Walls
2.63NI-wide·Technical Booklet G Resistance to the Passage of Sound
Do not (g) Do not try and convert a cavity separating wall to a type 1 (solid masonry) separating wall by inserting mortar or concrete into the cavity between the two leaves. (h) Do not change to a so
non-domesticflatssoundseparating-wallWall type 2.3 construction requirements
2.69NI-wide·Technical Booklet G Resistance to the Passage of Sound
Two leaves of lightweight aggregate block with 75 mm cavity and plasterboard on both room faces (see Diagram 2.17) – minimum mass per unit area including plasterboard 290 kg/m2; lightweight aggregate
soundnon-domesticWall type 2.4 – Aircrete blocks with cavity and plasterboard or plaster finish
2.70NI-wide·Technical Booklet G Resistance to the Passage of Sound
Two leaves of aircrete block with 75 mm cavity and plasterboard or plaster on both room faces (see Diagram 2.18) – minimum mass per unit area including finish 150 kg/m2; minimum cavity width of 75 mm;
soundnon-domesticdwellingflatsJunction requirements for external cavity walls with masonry inner leaf
2.71NI-wide·Technical Booklet G Resistance to the Passage of Sound
Where the external wall is a cavity wall – (a) the outer leaf of the wall may be of any construction; and (b) the cavity should be closed with a cavity stop (for wall types 2.1 and 2.2 see Diagram 2.1
non-domesticsoundexternal-spaceFramed inner leaf of external cavity wall - construction and finishing
2.76NI-wide·Technical Booklet G Resistance to the Passage of Sound
Where the inner leaf of an external cavity wall is of framed construction, the framed inner leaf should – (a) abut the separating wall; and (b) be tied to it with ties at not more than 300 mm centres
soundexternal-spacenon-domesticJunctions with timber ground floors
2.84NI-wide·Technical Booklet G Resistance to the Passage of Sound
If the floor joists are to be supported on the separating wall then they should be supported on hangers and should not be built in.
non-domesticdwellingsoundstructuralJunctions with concrete ground floors - solid slab
2.85NI-wide·Technical Booklet G Resistance to the Passage of Sound
A concrete slab floor on the ground should not be continuous under a type 2 separating wall (see Diagram 2.24).
non-domesticdwellingsoundJunctions with concrete ground floors - suspended
2.86NI-wide·Technical Booklet G Resistance to the Passage of Sound
A suspended concrete floor should not be continuous under a type 2 separating wall, and should be carried through to the cavity face of the leaf. The cavity should not be bridged (see Diagram 2.24).
non-domesticdwellingsoundContinuity of separating wall to roof
2.87NI-wide·Technical Booklet G Resistance to the Passage of Sound
Where a type 2 separating wall is used it should be continuous to the underside of the roof.
non-domesticdwellingsoundSeparating wall and roof junction closure
2.88NI-wide·Technical Booklet G Resistance to the Passage of Sound
The junction between the separating wall and the roof should be closed with a flexible closer (see Diagram 2.25).
non-domesticdwellingsoundReduced mass separating wall above ceiling
2.89NI-wide·Technical Booklet G Resistance to the Passage of Sound
Where the roof or loft space is not a habitable room and there is a ceiling with a minimum mass per unit area of 10 kg/m2 with sealed joints, then the mass per unit area of the separating wall above t
non-domesticdwellingsoundLightweight aggregate blocks sealing above ceiling
2.90NI-wide·Technical Booklet G Resistance to the Passage of Sound
If lightweight aggregate blocks of density less than 1200 kg/m3 are used above ceiling level, then one side should be sealed with cement paint or plaster skim of at least 150 kg/m2 mass per unit area.
non-domesticdwellingsoundWall Type 3 – Masonry Between Independent Panels: Sound Resistance Factors
2.93NI-wide·Technical Booklet G Resistance to the Passage of Sound
The resistance to airborne sound depends partly on the type and mass per unit area of the core, and partly on the isolation and mass per unit area of the independent panels. Note – Wall type 3 can gi
soundnon-domesticIndependent panels specification
2.100NI-wide·Technical Booklet G Resistance to the Passage of Sound
These panels should meet the following specification – minimum mass per unit area of panel (excluding any supporting framework) 20 kg/m2; panels should consist of either – (a) at least 2 layers of pla
soundnon-domesticdwellingWall type 3.1 - Solid masonry core with independent panels
2.101NI-wide·Technical Booklet G Resistance to the Passage of Sound
Solid masonry core (dense aggregate concrete block), independent panels on both room faces (see Diagram 2.27 and 2.28) – minimum mass per unit area of core 300 kg/m2; minimum core width is determined
soundnon-domesticdwellingWall type 3.2 - Solid masonry core with independent panels
2.102NI-wide·Technical Booklet G Resistance to the Passage of Sound
Solid masonry core (lightweight concrete block), independent panels on both room faces (see Diagram 2.29) – minimum mass per unit area of core 150 kg/m2; minimum core width is determined by structural
soundnon-domesticdwellingWall type 3.3 - Cavity masonry core with independent panels
2.103NI-wide·Technical Booklet G Resistance to the Passage of Sound
Cavity masonry core (brickwork or blockwork), 50 mm cavity, independent panels on both room faces (see Diagram 2.30) – the core can be of any mass per unit area; minimum cavity width of 50 mm; minimum
soundnon-domesticdwellingCavity closure requirements for external cavity walls
2.104NI-wide·Technical Booklet G Resistance to the Passage of Sound
Where the external wall is a cavity wall – (a) the outer leaf of the wall may be of any construction; and (b) the cavity should be closed with a cavity stop (see Diagram 2.31) unless the cavity is ful
non-domesticsoundexternal-spaceMasonry inner leaf bonding and lining requirements
2.105NI-wide·Technical Booklet G Resistance to the Passage of Sound
Where the inner leaf of an external cavity wall is masonry – (a) the inner leaf of the external wall should be bonded or tied to the masonry core; and (b) the inner leaf of the external wall should be
non-domesticsoundexternal-spaceMinimum mass requirement for masonry inner leaf with separating floor
2.106NI-wide·Technical Booklet G Resistance to the Passage of Sound
Where there is a separating floor the masonry inner leaf of the external wall should have a minimum mass per unit area of at least 120 kg/m2 excluding finish.
non-domesticsoundflatsMass requirement waived for lined masonry inner leaf without separating floor
2.107NI-wide·Technical Booklet G Resistance to the Passage of Sound
Where there is no separating floor and the masonry inner leaf of the external wall is lined with independent panels in the same manner as the separating walls, there is no minimum mass requirement on
non-domesticsoundexternal-spacePlaster or plasterboard finish for masonry inner leaf without separating floor
2.108NI-wide·Technical Booklet G Resistance to the Passage of Sound
Where there is no separating floor with separating wall type 3.1 or 3.3, and the masonry inner leaf of the external wall has a mass of at least 120 kg/m2 excluding finish, then the inner leaf of the e
non-domesticsoundexternal-spaceWall Type 4 – Framed Walls with Absorbent Material: General Guidance
2.135-2.139NI-wide·Technical Booklet G Resistance to the Passage of Sound
In this guidance only a timber framed wall is described. For steel framed walls, seek advice from the manufacturer. The resistance to airborne sound depends on the mass per unit area of the leaves, th
soundnon-domesticPoints to Watch – Wall Type 4 Construction Requirements
2.140NI-wide·Technical Booklet G Resistance to the Passage of Sound
Points to watch – Do (a) Do ensure that where cavity stops are needed in the cavity between frames they are either flexible or fixed to only one frame. (b) Do stagger the position of electrical socket
soundnon-domesticWall type 4.1 – Double leaf frames with absorbent material
2.141NI-wide·Technical Booklet G Resistance to the Passage of Sound
Double leaf frames with absorbent material (see Diagram 2.37) – minimum distance between inside lining faces of 200 mm; plywood sheathing may be used in the cavity as necessary for structural reasons;
soundnon-domesticdwellingflatsJunction requirements for wall type 4 - external cavity wall with masonry inner leaf
2.142NI-wide·Technical Booklet G Resistance to the Passage of Sound
Seek specialist advice.
soundnon-domestic