Fire protection for warehouses & industrial buildings

What you are required to do

Travel distance is measured along the aisle

This is the single most misunderstood requirement in a racked building. The 75-foot limit for Class A hazards is the distance somebody actually walks — down the aisle, around the end of the racking, across the floor. It is not the straight-line distance on a floor plan.

That means a warehouse can be reconfigured into non-compliance without anybody touching an extinguisher. New racking, a changed aisle layout or a tenant fit-out all move the walking route. The survey has to be re-walked, not assumed.

Match the unit to the hazard

• Flammable liquid storage — Class B coverage, and the travel distance drops to 30 or 50 feet depending on the hazard rating
• Welding and hot work — coverage at the work position itself, not at the wall thirty yards away
• Battery charging areas — a common and frequently unprotected hazard in any building running forklifts
• Spray finishing and solvents — Class B, sized to the volume actually stored
• Machine shops handling magnesium, titanium or sodium — Class D units, which are specialist and cannot be substituted
• Control rooms and server closets — CO₂, to avoid destroying the electronics you are trying to save

High ceilings change the alarm design too

Detection in a high-bay space behaves differently from detection in an office. Smoke stratifies and takes far longer to reach a ceiling-mounted detector, which is why beam detection and other approaches are used in tall buildings. If your warehouse has standard spot detectors at roof level, it is worth a conversation about whether they will actually see a fire in time.