Basement Floor Fire Resistance

[Martin Burford]

I wonder I there are any views on the following:

I am interested to know if the fire resistance of the floor from basement to ground in a building of 3 floors and basement with a single staircase should be 1 hour, with 2 x 30mins doors protecting the stairs at basement level. Also all FRSC doors throughout the building are on auto releases. The building listed Grade II and is used as offices.
Many thanks
Conqueror.

[CivvyFSO]

New/altered building:
ADB 8.18c says it should be compartmented.
Table A2 gives 60 mins for offices.

Clearly its existing so: New guides recommend 2 x 30min doors to a protected stair, and also states that floors above basements should be 60 mins, 30 mins may be ok in smaller premises, BUT if there is a reasonably imperforate floor then AFD may be a reasonable compensatory feature instead of FR. In the guide the fire doors create a lobby at basement level, which is preferable from a firefighting perspective, but I would be happy with a door at the head of the steps and a door at the bottom.

IMO, risk assessed of course... 1 60 minute door at the basement level with AFD should do the job. Any fire in the basement is picked up and people are out of the 60 min door before smoke getting into the staircase is an issue, so the staircase remains well protected for the remaining persons travelling down.

[Martin Burford]

Many Thanks Civvy
Much The Same As My Thoughts, However Not So Sure About The Automatic Releases On Single Staircase Condition.
Also The Staircase A
From Basement To Ground Has No Fr Doors Bottom Or Top Just The Basement Rooms Off The Staircase Also On Auto Releases.
Conqueror.

[CivvyFSO]

You Will Wear Your Shift Key Out Typing Like That.

[AM]

Probably won't apply, but watch out for any Local Act that may have required a higher level of fire resistance for the building than what ADB recommends, which would have to be maintained under the FSO.

[kurnal]

If the basement is also occupied as office accommodation I would prefer automatic releases over the potential use of wedges even in a single staircase building, as it will get a lot of traffic, wear and tear, and the liklihood of it being wedged will be much higher

If the basement is put to other uses eg storage then I would expect to to see the door closed and probably locked shut.

[CivvyFSO]

I was thinking the same actually. If automatic releases are installed it immediately stops the possibility of the door being wedged. It's the same old problem though, it needs to be maintained properly because it immediately becomes a life safety system and it quite simply HAS to work to protect persons above.