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Party Wall Sock
Data Sheet


CCL Party Wall Sock consists of a length of flexible mineral wool slab fully enclosed in polythene.


CCL Party Wall Sock is designed to minimise sound transmission and fire penetration through the wall cavity adjacent to separating floors.


  • Fire, thermal and acoustic solution
  • Simple to install
  • Supports compliance with Part E Building Regulations
  • Maintenance free


CCL Party Wall Socks are supplied in 1200m lengths, normally 300mm or 380mm wide, and are factory cut to suit cavity widths from 50mm to 150mm.

Standards and Performance

The mineral wool core of a CCL Party Wall Sock achieves a fire classification of Euroclass A1 as defined in BS EN 13501 – 1.

The correct use of a CCL Party Wall Sock will exceed the requirement to provide a 30 minute cavity fire barrier as defined in Approved Document B of the Building Regulations 2010 (2019 edition) Table B3 of Appendix B.

The product has been independently tested adopting procedures and criteria from BS476 : part 20 : (1987) and achieved 1 hour fire resistance.

Approved Document B of the Building Regulations 2010 (2019 edition), Section 8 details the requirement and purpose for which a cavity barrier should be installed.

CCL Party Wall Socks comply with the robust details accepted to provide a solution which satisfies the Approved Document E 2003 (2015 edition) of the Building Regulations relating to the transmission of sound.


CCL Party Wall Socks are supplied 10mm to 15mm thicker than the cavity in which they are to be installed and friction fitted during the brickwork process.

During vertical installation it is necessary to place a length of damp proof course between the Party Wall Sock and the outer leaf.

During horizontal installation it is advisable to protect the Party Wall with a damp proof course or proprietary cavity tray immediately above with a minimum 100mm upstand.

Special attention must be paid to the joints to ensure that these are very closely butted. Cavity barriers may fail at the joints if a gap is left.

The Party Wall Sock is fitted under compression and should bridge the whole cavity leaving no gaps.

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