Compartmentation requires walls, ceilings and structural elements to have proven fire resistance characteristics. It’s vital that these compartment elements deliver the required performance in real situations, not just in simpler fire test configurations. For instance, the corners, the connections with other walls or ceilings, the suspension and hanging elements, the fixing methods and joints are all critical points and should be analysed and tested under real world conditions.
All holes, joints, passages of pipes or cables should be adequately protected because these penetrations can become a route for fire and smoke spread and consequently undermine the compartmentation principle.
Gaps and openings in large areas, such as floors in common service shafts, should be fully and properly sealed using the appropriate products and systems employed for sealing such gaps and openings. Such gaps also include any joints or open spaces due to poor workmanship or those left for designed structural movement.
One of the most important design considerations is also to include multiple escape routes and, in the case of tall buildings, at least two staircases placed far apart. The staircases must be pressurized, designed to be fireproof compartments that keep smoke out. The staircases and, in general the escape route, should be always kept clear of combustible materials and fabricated, as much as possible, with non-combustible materials.
Some national regulations allow the construction of tall residential buildings even with one staircase, provided that they are appropriately designed, while others allow a performance base approach (so called fire safety engineering), requiring designers to themselves evaluate the number of stairways and the evacuation times.
Key passive protection measures are safety zones or super-efficient compartments – which are uninhabited floors or rooms designed to resist the spread of fire for much longer than normal.
From an evacuation perspective, refuge floors present several advantages: they are a place of rest for the evacuees; the possibility of having stairs or lift shafts filled with smoke is reduced; they can be employed to protect people with disabilities and/or injured evacuees; they can be used as a command point for rescue teams to assist evacuation; and they can serve as a fire-fighting base.
Any passive protection system is, of course, only as good as the installation process. In each country, relevant local fire building codes and legislation apply.