Fire Doors

[malmofire14]

What is the reasoning behind 60 minute fire resistant walls only requiring 30 minute doors in some blocks of flats.

[Tom Sutton]

I believe this has been around for some time and I can go back to the 1972 regs but I have never been able to find the answer however I will have another go and if I find out anything I will be back.

[Tom Sutton]

The wall between a flat and the common areas is a compartment walls and tested to BS 476 part 21 which includes stability as well as integrity, so it needs to remain stable as well as resist the passage of fire for the appointed time (60 mins). Fire doors are non-load bearing and tested to BS 476 part 22 for integrity, I have chosen to ignore insulation because it is not relevant in this discussion.

Therefore compartment walls have remain stable and resist the passage of fire for the full 60 minutes and fire doors only have to resist the passage of fire. Because fire doors do not have to remain stable you can have two doors protecting the opening, one from the habitable rooms to the hall and then a second (front door) from the hall to the common areas a combination of 60 minutes.

[Safelincs]

Hi Tom

That is a quality answer!

Harry

[Tom Sutton]

Thanks Harry but I have been told off by Colin Todd who says,"Tam, you are making it all too complicated and your explanation does not take into account flats with no internal fire doors". I am now awaiting his simplified answer.

[Safelincs]

It will be interesting to hear Colin's view

[Tom Sutton]

Check out http://fire.org.uk/forum/index.php?topic=6252.0 and follow the thread wee b is an building control expert see what he has to say.