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Fire Stop Strip

Verified by manufacturer 3 months ago


Fire and smoke stop for linear gaps or imperfections of fit in buildings.

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+44 (0)1293 582400


  • Top of masonry wall under soffit.
  • Above partitions.
  • Expansion joint in masonry wall.
  • Within metal cladding systems.
  • Between ceilings and walls.
  • Suitable for horizontal and vertical applications.


AIM Fire Stop Strip is made from high density Rockwool stone wool and is permanently held in place by compression without the need for adhesive or intumescent mastic. It prevents the passage of flame and smoke through the void being fire stopped. For gaps greater than 100 mm above masonry walls and partitions use AIM Partition Head Barrier.

AIM Fire Stop Strips have been developed to prevent the passage of fire and smoke in narrow voids in constructions such as the junctions of compartment walls and floors. The Fire Stop Strip will accept deflection from the floor above and can be used to seal imperfections in the wall construction.

AIM Fire Stop Strip is manufactured in lengths of 1200 mm with depths and widths to suit the void size (with an additional 5% depth to allow for the compression fit).

Features and benefits:

  • High density stone wool strips, typically supplied 1200 mm long.
  • Up to 400 mm wide and suitable for voids of up to 100 mm.
  • Tested to EN 1366-4.
  • Global warming potential = zero.
  • Prevents the passage of fire and smoke through the void.
  • Will help prevent the passage of sound through the void.
  • Can be used as a movement joint in masonry walls when used vertically.
  • Simple to install – no tools required.
  • Up to 2 hours’ fire rating.
  • No mastics or sealants required.
  • Fixing clips are required in applications where the product is unsupported.

General information



Natural stone wool.


Stone wool

High density stone wool.




1200 mm


Widths from 75 mm to 400 mm.


75 mm

400 mm


Thicknesses from 10 mm to 100 mm.


10 mm

100 mm


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




To EN 1366-4.

Fire performance

  • Fire Stop Strip is designed for closing small voids up to 100 mm.
  • Not tested in cavities over 100 mm.

75 mm: Masonry to masonry: EI 120/60; Masonry to softwood/ OSB/ CP board/ SFS: EI 30/30. 100 mm: Masonry to masonry: EI 120/120; Masonry to softwood/ OSB/ CP board/ SFS: EI 60/30.

Application: integrity/ insulation.

Sound insulation rating

AIM Fire Stop Strip provides at least RW 14 dB sound reduction. The acoustic performance of the floor and wall systems must also be considered when assessing the room-to-room sound reduction figure.

75 mm long block: RW 14 db, 100 mm long block: RW 18 db, 140 mm long block: 23 db RW.


1200 mm.


For voids 10 mm to 100 mm.

10 mm.

100 mm.


Insert requirements.


75–400 mm.

75 mm.

400 mm.


Consult manufacturer and insert requirements.


AIM fire barriers are chemically inert, will not sustain vermin and do not encourage the growth of rot, fungi, moulds or bacteria.

They do not degrade under the usual conditions found in buildings and will perform effectively for the life of the building.


Compatible with all normal building materials.


Global warming potential = zero.

AIM fire barrier products are manufactured from stone wool insulation which is universally recognised as being a sustainable and environmentally friendly material.


AIM Fire Stop Strip Technical Guide 2022

AIM Fire Stop Strip Technical Guide 2022

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