Fire protection for automated storage
Conventional ceiling sprinklers were never designed for narrow-aisle, extreme-height storage packed with plastic totes. That mismatch is why fire protection for automated storage is treated as its own engineering discipline, not an extension of a conventional warehouse's sprinkler system.
Last updated 2026-08-24
Why dense automated storage is a different fire problem
Ceiling sprinklers rely on a fire being detected and suppressed from above, with the water able to penetrate down through the stored goods to reach the seat of the fire. Tall, narrow-aisle automated storage using plastic bin or tote systems works against that assumption on every count: the aisles are too narrow and the storage too tall for water to reliably penetrate from ceiling height alone, and plastic totes burn differently, and often more intensely, than the cardboard cartons and timber pallets a conventional sprinkler design assumes. That height and density is the same clear-height decision driving the structure in the first place.
This is genuine, active fire-engineering territory rather than a marketing point — testing and standards bodies treat it as a distinct problem from conventional racking fire protection, not a scaled-up version of the same one.
In-rack sprinklers, as a distinct system
The engineering response is to bring suppression into the racking itself, with sprinkler heads mounted at intervals inside the storage structure rather than relying on ceiling coverage alone. That makes the sprinkler system, in effect, part of the racking structure the same way a stacker crane's rail or a shuttle system's guides are — one more reason a rack-supported ASRS structure needs to be engineered as a single system rather than a building with equipment dropped into it. It sits alongside, rather than instead of, the kind of physical protection conventional racking already uses, like column guards and rack protection against forklift strikes.
Performance-based design versus prescriptive rules
Where a prescriptive fire code doesn't have a ready-made answer for a particular ASRS configuration, testing bodies such as UL Solutions run performance-based fire testing — actual fire tests against a documented protocol, rather than applying a generic rule — to establish whether a specific in-rack sprinkler arrangement genuinely extinguishes, not just suppresses, a fire under realistic conditions. This page won't restate specific spacing, density or piping figures from any individual test result: those numbers are configuration-specific to the exact storage height, tote type and sprinkler arrangement tested, not a general design requirement that carries across every site.
In the United States, this sits alongside NFPA 25, the standard covering inspection, testing and maintenance of water-based fire protection systems, and FM Global's own performance-based testing standard, FM DS 8-34. What the equivalent Australian code pathway looks like for a specific ASRS project — which parts of the National Construction Code and which referenced standards apply — wasn't confirmed in the research behind this page, and needs a fire engineer engaged on the actual building, not a general answer from an article.
Why in-rack systems are harder to look after
In-rack sprinkler piping sits inside the storage structure, often at multiple levels, which makes it materially harder to access, inspect and maintain than a ceiling-mounted system a technician can walk under. Leaks, blockages and physical damage from handling equipment are all real risks specific to in-rack placement, and none of that maintenance need goes away because the storage around it is automated.
What this doesn't change
Fire protection engineering for an automated storage facility is a separate discipline from racking structural inspection, run by different specialists against different standards — see AS 4084 for what governs the racking side of that separate discipline. Automating the storage doesn't reduce the need for either, and it doesn't reduce the need for a competent person to still assess the racking itself. A well-designed in-rack sprinkler system says nothing about whether the racking steel it's mounted to is structurally sound, and a structurally sound rack says nothing about whether the fire system inside it still works.
Common questions
- Why can't ceiling sprinklers handle automated high-bay storage?
- Narrow aisles and extreme storage height make it hard for water from ceiling-mounted sprinklers to penetrate down to the seat of a fire, and plastic tote and bin systems, common in automated storage, burn differently to the cardboard and timber a conventional sprinkler design assumes.
- What is an in-rack sprinkler system?
- A sprinkler system with heads mounted at intervals inside the racking structure itself, rather than relying on ceiling coverage alone, engineered to suppress fires that ceiling sprinklers can't reach effectively in dense automated storage.
- Does Australia have its own fire code for automated storage?
- The research behind this page didn't confirm the specific National Construction Code pathway or referenced standards that apply to a given ASRS project in Australia. That needs to be confirmed with a fire engineer for the actual building, not assumed from overseas standards.
- Does a good fire protection system remove the need for racking inspection?
- No. Fire protection and structural racking inspection are separate disciplines addressing separate risks. A sound fire system says nothing about whether the racking steel is structurally sound, and vice versa.
Sources
- UL Solutions — New Challenges in Fire Safety in ASRS Warehouses — Independent third-party testing body describing why dense automated storage needs performance-based fire design; figures from its case study are deliberately not restated here. Retrieved 2026-08-23.
- Damotech — Fire Sprinkler Safety Requirements in Warehousing — Industry summary referencing NFPA 25 and in-rack sprinkler inspection and access challenges. Retrieved 2026-08-23.
Part of our guide to warehouse automation.