Grooves on the edge of a fire door routed too deep for the cold smoke seal

[Guest Paul]

Hi everyone,

I have encountered a 30 minute fire door that has been routed too deeply for the fitting of intumescent/ cold smoke seals. The cold smoke seals are now flush with the edge of the door, thus making them ineffective.  Could anyone please tell me if there is an acceptable repair technique to correct this..

Thank you in advance for the assistance.

Paul

[Neil ashdown]

For FD30(s) timber-based fire doors the intumescent seal size is usually 4mm thick x 10mm or 15mm wide so and the seal should fit tightly in the groove and flush with the edge of the door leaf.  The integral brush or blade should only lightly contact the opposing surface, ie. the one that it sweeps or compresses against.

So if the groove is too deep, it would be necessary to cut a fillet from thin hardwood or MDF to fit tightly into the groove behind the intumescent seal. Ensure that the fillet is continuous and that there are no voids behind the seal.