5. Staircase smoke extraction (DF 5)

Enclosed staircases can be de-ventilated by natural sweeping or overpressurization in relation to the adjacent volume(s).

Mechanical smoke extraction is strictly prohibited.

A non-enclosed staircase does not need to be cleared of smoke if the volumes with which it directly communicates (levels, rooms, corridors, etc.) are not required to be cleared of smoke.

For smoke-free areas, the staircase must be :

• separated from lower levels by enclosure screens ;

• The volume with which it communicates can be used to remove smoke from the upper...