AIM Partition Head Fire Barrier

A semi rigid stone wool slab for closing cavities from 100mm up to 600mm above the line of a fire rated partition. Foil faced Rockwool stone wool fire and smoke stop for large gaps above partitions and masonry walls. AIM Partition Head Fire Barrier is made from foil faced high density Rockwool stone wool and provides a fire barrier above fire rated metal frame partitions, fire rated timber partitions and masonry walls. Rockwool red logo

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  • Lengths: 1000mm
  • Voids: 100 - 600mm (Less than 100mm use AIM Fire Stop Strip)
  • No mastics or sealants required
  • Tested to BS 476 part 20 and assessed by Warrington Fire Research Centre
  • Non-combustible to EN13501-1 and classified A1
  • Complies with performance requirements of Class O Building Regulations
  • Warming potential = zero
  • CFCs or HCFCs used in manufacture

Fire Performance

The performance of AIM Partition Head Fire Barrier has been tested to BS 476 part 20 assessed by Warrington Fire Research Centre.

Fire Resistance Minimum Thickness of Fire Stop mm
Minutes Gaps 101 ->
Gaps 301 ->
30 50 75
60 75 100
120 100 100 with lap join
240 100 EHD* NA

Thickness is measured as the distance between one compartment and the next, which the fire stop or barrier is separating.


In a fire situation a partition may bow appreciably due to the heat of the fire on one side with the result that the partition head may move laterally to a significant degree. AIM Partition Head Fire Barrier is supplied with a clip system to prevent the possibility of it being dislodged and therefore ineffective in a fire situation. For voids over 250mm link straps are supplied in addition to clips in order to restrain lateral movement of the partition head.

Two clips are inserted into the base of each length of AIM Partition Head Fire Barrier. The barrier is push fitted into place and it must fit tightly and completely; the clips are then screwed to the top of the partition or wall.

The Barrier must be compressed by about 5% when installed. The maximum void size is 600mm. Where the gap exceeds 250mm, the top of the partition or wall must be securely fixed by steel fixings to the soffit using steel link straps (see diagram on PDF).

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