Product description

Retrofit construction can often present a challenge when it comes to fire protection any works undertaken can compromise existing firestopping. Our expert Intumescent Expansion Joint Seal offers a solution to make sure that all pre-existing construction offers maximum fire insulation.  


ROCKWOOL Intumescent Expansion Joint Seal is suitable to fill construction joints of up to 75mm thick within floors and walls to add extra fire prevention. Available in a wide range of sizes to suit any project, this compressible design is formed through taking a ROCKWOOL core and shrink wrapping a graphite-based intumescent polymer to each face. If a fire were to occur, this strip would swell to form a hard char in a fire, preventing passage of fire and smoke. This product is easy-to-use and can be compressed to the required length by hand and then inserted into the joint without the need for adhesives or intumescent sealants. Exclusively for linear joint in walls, this seal is made specially to protect blockwork cavities, curtain wall and concrete slab interfaces as well as expansion and structural joints.



Complies with BS476: Part 20 (1987) regulation.

IFC Certified


  • Maximum protection – ROCKWOOL Intumescent Expansion Joint Seal offers 4 hours of fire resistance, creating a lasting protection against fire and smoke passage.
  • Available in small quantities – by giving greater customer choice, this product can be an economical solution.
  • Water resistance – don’t fear rain, leakages or floods, ROCKWOOL Intumescent Expansion Joint Seal is 100% resistant against water.
  • Zero maintenance – requires no ancillaries, which makes it a cost-effective solution in the long term.