Fire Stop Strip

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


AIM Fire Stop Strip is made from high density Rockwool stonewool 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 100mm 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 Strips have been tested for use with a variety of wall constructions including timber framed, SFS with CP board facing as well as conventional masonry.

Typical applications include:

  • Top of masonry wall under soffit
  • Above partitions
  • Movement joint in masonry wall
  • Within metal cladding systems
  • Between ceilings and walls
  • Metal Decking, Roofing and Cladding


  • High Density Rock stonewool strips typically supplied 1200mm long
  • Up to 400mm wide and suitable for voids of up to 100mm.
  • Suitable for horizontal and vertical applications


  • 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.
  • No mastics or sealants required


• Lengths: 1200mm
• Widths: up to 400mm
• Voids: 10 - 100mm


AIM Fire Stop Strips are generally packed into cartons and stretch wrapped onto wooden pallets with a showerproof polythene pallet cover and high quality edge protectors.


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


AIM Fire Stop Strips are often used in conjunction with AIM Fire Stop blocks. The Fire Stop Strip will accept deflection from the floor above and can be used to seal imperfections in the wall construction


Where a fire wall is built to the underside of a perforated metal deck, AIM Fire Stop Blocks should be installed above and below deck at the line of the wall to ensure that smoke or fire is prevented from passing through the perforations in the metal work.

AIM Fire Stop Strip can also be used to remove any imperfections in the head of the wall to the underside of the metal deck.

AIM Acoustic Trough Infills are then used across the metal deck, to assist with the reduction of noise reverberation from within the building.

The performance of the AIM Fire Stop Block is dependent on the metal deck remaining stable in a fire situation and should be assessed by a competent person.



Fire Rating Cavity width 100mm

Fire rating (integrity / insulation) - all horizontal and vertical use

Masonry to MasonryYes120/60120/120
Masonry to SoftwoodYes30/3060/30
Masonry to OSBYes30/3060/30
Masonry to CP Board / SFSYes30/3060/30

Fire Stop Strip is designed for closing small voids up to 100mm.

It is installed under compression (minimum 5% compression required).

It should be installed with fixing clips (except at the head of a masonry wall).


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

75mm long block = 14dB RW
100mm long block = 18dB RW
140mm long block = 23dB RW


WF 432745
WF 399452
WF 414885
Z11012 – Acoustic Performance – Testing on mineral fibre insulation. To BS EN ISO 10140-2.


More drawings available in the Technical Guide which can be downloaded above.


AIM Fire Stop Strip must be compressed by minimum of 5% compression, when installed. It is push fitted into place and must fit tightly and completely; all butt joints also must also be tight. Where rough masonry surfaces cause problems a small piece of metal or plastic sheet may be temporarily inserted as a slip plate. The plate should be removed once installation has been completed.


• PPE abrasion resistant gloves
• PPE impact resistant goggles
• RPE dust mask


Products are supplied in cartons and on wooden pallets with edge protection and a shower proof hood. Products should be stored away from the elements until ready for installation.


This product does not contain moving parts and, if undisturbed in the cavity, requires no routine inspections or maintenance.

It is recommended that the integrity of the barrier is rechecked if further works are carried out, which may involve disturbing the product.


AIM fire barriers are chemically inert, will not sustain vermin and do not encourage the growth of rot, fungi, moulds or bacteria. They are compatible with all normal building materials. They do not degrade under the usual conditions found in buildings and will perform effectively for the life of the building.


Insulation products supplied by AIM are considered to be inert articles and as such are exempt from requirements to provide a Safety Data Sheet.

A Product Safety and Handling Information Sheet is available upon request.


Global warming potential = zero

For product recycling please contact: Rockwool
T: 01656 868400 e: [email protected]


To order this product the following information will be required:

• Void depth in mm.
• Fire Performance required.
• Approximate quantity.
• Delivery location.

All AIM fire barriers are made to order. Products are typically supplied in seven to ten working days but lead times may vary depending on existing factory commitments.

There is no minimum order quantity or value although small orders may attract transport surcharges.


Technical Support is available from our experienced sales team on 01293 582 400 or [email protected]

Our Partners & Affiliates

AIM are partners with NBS. Our products can be found on NBS Source and have been authored to NBS specification standards and have both CAWS and Uniclass 2015 classifications.

AIM are members of ASFP.

AIM are working in partership with Rockwool.