Extended pile brush strips

[Barney057]

I wonder if anyone has any thoughts on the use of extended pile intumescent brush strips to create a cold smoke seal where the gap around a nominal fire door is greater than 4mm.

 

Thanks in advance for replies

[Neil ashdown]

If the gap is more than the widely accepted '4mm rule' then there is greater risk that the door will fail to meet its intended fire resistance performance.  Make sure your fire risk assessment deals effectively with this non-compliance issue.