On 30/01/2021 06:06, jon wrote:
On Fri, 29 Jan 2021 16:00:17 +0000, Jimmy Stewart wrote:

On 29/01/2021 15:46, Brian Gaff (Sofa) wrote:
Cannot see it but to my mind once the room is alight enough to cause
that sort of need you are pretty stuffed anyway and should be in the
street with your mobile waiting for the fire engine.
Brian

but one hour FR gives the people on the floor above time to ext.....

What people on the floor above ?

in general fire barriers and structural integrity are good enough at the
45 minute mark, which is how long the twin towers lasted. 45 minutes is
enough to get the people out - if they can be got out.

Fire policy is part containment, part fast evacuation routes. The idea
is to keep the fire contained until the people are out

So a ceiling fire barrier stops the joists catching fire above it. For a
while. If it's a concrete ceiling/floor above it, it is of course
pointless.


Most fire caps for lights and so on are ********
Half the time there are pipe runs and voids ready to carry fire up
building interiors - or in the case of certain tower blocks - the
outside as well


--
Religion is regarded by the common people as true, by the wise as
foolish, and by the rulers as useful.

(Seneca the Younger, 65 AD)