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ROCKWOOL Fire Barrier Slab is an aluminium foil faced slab used to close voids of up to 1m in height and 20m in length supported by a masonry wall (minimum density of 400 kg/m3) offering the same fire performance.

The slabs are cut to height and friction fitted within the opening. ROCKWOOL Acoustic Intumescent Sealant or ROCKWOOL LUL Intumescent Sealant is applied to the butt joints and perimeter of the barriers.

Rockwool insulation products do not contain blowing agents with an ozone depletion potential (ODP) or global warming potential (GWP), are CFC-HCFC-HFC free and 97% recyclable. They will not react with metal components or cause loss of plasticiser from PVC cables and pipes.


  • Fire Barrier Systems offer labour-saving solutions to prevent the spread of fire and smoke within roof and ceiling voids.
  • Ease of construction and installation reduces the risk of installation errors.
  • Systems available to provide up to 4 hours Fire Protection.

Standard product features


1000 x 666 x 100 mm.


Foil faced both sides.

Reaction to fire class:

A1 to BS EN 13501-1.


  • Non-combustible, achieving a classification of A1 in accordance with BS EN 13501-1.
  • No penetrations - 4 hour integrity; 1 hour insulation Service penetrations 1½ hour integrity; 1 hour insulation when subjected to BS 476:Part 20 and 22: 1987 – reference WFRC – report C122729.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-45-70/385 Mineral wool slab insulation

Product specification

An important note about specifying





+44 (0)1656 862621

Product reference

ROCKWOOL Fire Barrier Slab


[ROCKWOOL Acoustic Intumescent Sealant]
[ROCKWOOL LUL Intumescent Sealant]

Manufacturer details

14th Floor, Chiswick Tower,
389 Chiswick High Road,
London, W4 4AJ
Tel +44 (0)1656 862621
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