One of the biggest failings we find in fire detection system installations during our inspection process is the lack of fire detection in the stairwells.
Even though fire detection designers/installers classify their systems as an L category system, fire detectors are missing from the stairwell.
On investigation of this situation the common answer given is: “there is no risk of fire in a stairwell, there is nothing to burn, so why protect it?”
WHY?
L category fire detection systems are life safety systems therefore installed to protect the occupants of the building and provide them a safe means of escape from the building in a fire scenario.
Smoke and heat from any fire, in most cases rise, smoke from a fire starting in the basement or ground floor will seek out routes to rise, which will be the stairwell, lift shafts and service ducts which could then leak out at higher levels into the passages and corridors. Persons working in their offices or sleeping in a hotel room etc will be unaware of such smoke penetration if there are no smoke detectors in the hallways or stairwells.
In a multi storey building smoke may leak out of the stairwell or lift shaft fill up the corridor, leak through the door crack into a room and set the fire detector off in that room. The lifts will home and all persons have only one route to evacuate the building, down the stairwell that is now smoke logged; will they make it, will they survive, who knows?
The National building code SANS 10139 provides five categories of L (Life) safety systems, the entry level category L4 demands fire detectors to be installed in all escape routes, corridors and stairwells.
All other categories, L3 to L1 follow on from L4 and must include L4. Installing fire detectors into rooms is secondary to those in the corridor when protecting lives. It is not a life safety system if fire detectors are not installed in the stairwell or the escape corridors!!