Daniel Green

I agree. The specific guidance you can use is the LGA "fire safety in purpose built blocks of flats". Although a bit old, it still hasn't been superseded.

The single most important thing you should do is to ensure that there is adequate early warning fire detection installed. As a minimum this should be installed on an LD2 basis (heat detector in the kitchen interconnected to smoke detectors in the corridor). The smoke detectors should be loud enough to wake sleeping occupants and you should test these on a monthly basis. If you are concerned that they are not loud enough or have other concerns, you could upgrade them to have LD1 coverage (interlinked detectors in all rooms). The other thing you should do is to ensure that your escape route from the furthest point in the house to the final escape door is kept clear at all times.

I am hoping someone can give some advice here, as I can't find any anywhere else! I am fully aware that gaps around modern fire doors should be 3mm (+/- 1mm) and this is because the intumescent strip and smoke seal are rated for gaps that size. However, I conduct a lot of fire risk assessments for residential blocks of flats built in the 1970s and 1980s where the CP3 standard applied, requiring 25mm rebates. The requirement for that standard was the door to be flush against the rebate, to prevent smoke and fire from getting past. In accordance with the LGA guidelines, and also BS 9794 (Clauses 9 and 10.4) I am happy to accept these doors in principle, including the two hinges, on the basis that they are fully self-closing. However, my questions is about the gaps around, and what are the tolerances permitted, but nobody seems to know about this. It seems to me, that the 3mm requirement should only apply to fire doors where there is a reliance on an intumescent strip and smoke seal, so what tolerance should I accept for these "notional" fire doors? Would say a 5mm gap be acceptable? Or maybe larger one, provided the door frame fits tightly against the rebate (ie up to 25mm)? Thanks in advance for any advice