This is a story about how we can all save lots of money for our clients, by learning how to distinguish a fire door from a fire rated access panel by its function, despite their twin-like appearances.
Our high-rise projects often provide service risers to distribute and collect water, air and telecoms to and from the building occupants. Good design allows for maintenance of these services throughout the life of a building. The most common solution to provide floor to floor access is a door. Most service riser shafts are built with a fire resistance rating to protect against the spread of fire from floor to floor. An opening in a fire rated shaft needs a fire rated closure or fire door.
Fire doors are most commonly thought of when used to separate adjacent fire cells along egress routes for people to pass through in ordinary business and when leaving a building in a fire. Fire doors must be self-closing and self-latching so that with any human interface, its position fails safe to always closed. So, we add a door closer and a fire rated latch tested to perform.
In our design documentation we refer to fire doors principally to recognise their function as a closure in a fire separation between fire cells. But doors to protected shafts do not function like room entry exit doors, or stairwell entry exit doors. Services riser access doors usually get wedged open so a service person can stand at the doorway and maintain building services. They generally do not enter the service shaft and shut the door behind them. A door to a service shaft will function as a closure in a fire separation between fire cells but it will not function as a means of human egress in a fire. If a fire happens while a service riser fire door is open, the technician will first extricate themselves and their tools from impeding the doorway, then un-wedge the door, let it shut and latch, before exiting the building. Rarely is a door to a service shaft ever opened.
“A door closer on a rarely opened door, that when opened, is wedged open, serves no useful purpose.”
The alternative to a fire door opening in a protected service shaft is a fire rated access panel. These do not have to be self-closing or self-latching like a fire door, but they must only be capable of opening with a special tool, to prevent casual access. You can save the expense of door furniture, (handles), and door closing hardware on all service riser doors, think multi-storey hotels, apartments, etc, if you rename your “fire door” and call it a “fire rated access panel”. The Building Code acceptable solution recognises Protected Shaft Access Panels. Your special tool can be a key to a door latch. Expect to save many tens of thousands of dollars on ALL substantial sized buildings.
To make this happen, our architects need to document fire resisting closures as either doors or access panels (that look like doors), so the appropriate door hardware can be designed to meet Building Code functional requirements as a Fire Door or a Protected Shaft Access Panel.
I am grateful to Tony Richards, who saw the problem that inspired this solution, (25+ years ago).
Technical Notes;
[1] A fire door, to a protected shaft, that is reclassified as an access panel, ideally will still have a latching mechanism, because it must “only to be open-able with a special tool”. An access panel, that can swing shut, without latching, is closed “unlatched”, and can be opened without a special tool.
[2] You can reclassify existing building fire doors to protected shafts as access panels, but this requires a building consent, to change your Compliance Schedule.
By Matthew Ensoll Life Member NZIQS. Reg.QS.
Editor New Zealand Building Economist.