40m run - 60 min doors of blocks with open balconies

[Fire Monkey]

Hi,

I recently saw a block of flats with open balconies that have a one way travel run of around 40m (dead end and flats having to pass another flat in order to escape). There is no viable way to install a 2nd means of escape (without extensive building works), no communal fire alarm system, no cladding and the building has no significant risks. Escape abilities of occupants not known.

With open balconies one would normally specify a FD30 (and sets) for each flat door but given the run that is over double the 18m for single way travel it has been suggested that a FD60 or even a FD60S fire door for each property would be more suitable.

Now I know you would not be familiar with this property but in general what are your thoughts about the FD rating? Have you come across similar situations and was there a specific risk factor determination that led down a particular route for appropriate upgrades to passive or active systems.

Best regards,

[Fishy]

Personally, I couldn't come up with any credible argument that by increasing the fire resistance of doors from flats onto communal areas above that recommended in national guidance you adequately address a means of escape issue, not least because there's a foreseeable risk that the occupants will leave them open as they escape.

[Fire Monkey]

Well I can't see any reason as to why 60min doors are required so I can only support a recommendation for FD30 ones. All of the window sills are 1.1m high so there is space to craw under windows if required - since the cause of a fire is likely to be in the kitchens (that face the balconies) the windows there will blow way before any fire has gone through the 30min kitchen door and the front door.