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Party Wall Fire Closers

Party Wall Fire Closers


Semi-rigid Rockwool stone wool to polythene damp proof course cavity closers for the junctions at party walls.

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Designed to provide at least one hour resistance to the spread of fire past the party wall of adjoining buildings. It also significantly reduces flanking sound transmission within masonry wall cavities.


  • Rockwool stone wool: 1200 x 300 mm, available in six thicknesses.
  • Damp proof course polythene: 1300 mm long, 40 mm side lap and 100 mm end lap. Conforms to BS 6515:1984.

Fire performance to BS 476-20:

One hour (provided the bearing width of the closer on each side of the cavity wall is at least 100 mm), assessed by Warrington Fire Reach Centre.

Surface spread of flame to BS 476-7:

Class 1 rated.


Can be used to prevent the passage of flanking sound within masonry cavities and complies with Building Regulations (E&W) Approved Document E 2003 and the requirements of Robust Details.


Ozone depletion potential of zero. No CFCs or HCFCs used in manufacture.

General information


Pr_25_80_81_51 Mineral wool fire-stoppingPrimary


P12/360 Mineral wool rigid batts

P12/40 Mineral wool rigid batts

Product range

Fire Barriers

Specification data - Mineral wool fire-stopping

Product Reference

Party Wall Fire Closers


50 mm

65 mm

75 mm

90 mm

100 mm

120 mm

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