Warehouses face the threat of fire in several different ways, whether it’s due to flammable inventory, faulty electrical, or intentional arson. There are several methods to prevent fires, but there may come times when a fire will ignite regardless; that’s when you need to know how to stop the spread as quickly as possible.

To halt the fire from spreading, you must know the requirements for pallet racking flue space. Flue space is an essential aspect of fire suppression in the warehouse and something you need to familiarize yourself with before a fire event.

The Two Types of Flue Space

Flue space is an area in and around your racking system that can be separated into two different types: longitudinal and transverse. Both are necessary for fire suppression and something you need to inspect when auditing your fire-response measures.


These are the spaces that run between rack rows that are perpendicular to the direction of loading. Generally speaking, the distance between your rows should be about six inches.


Transverse refers to the distance between individual pallets on a shelf, ensuring that they are not too bunched up.

The Goal of Flue Space

Hot air travels upwards, but there need to be clear pathways to allow the heat to rise. Longitudinal and transverse flue space ensures that the heat will make its way up to the sprinkler system, setting it off and raising the alert system.

Don’t Neglect the Decking

Flue space effectively allows hot air to travel up, but you still need a way for water to travel down. In this case, you need to invest in slotted pallet rack decking to ensure the water continues to flow downward instead of pooling on any one shelf. Your preventative measures won’t do much good if the sprinklers cannot reach the fire below.

Stop the Spread of Fire in its Tracks

Everything you implement, whether it’s the sprinkler system, flue space, or decking, plays a role in mitigating fire damage. Be aware of the requirements for pallet racking flue space and always be conscious of blockages, push-through, or solid rack decking. Reach out to Rack Safety Products for more information on flue space and our flue guards.