When you look at a fire rated grille and a non-fire rated grille, they appear almost identical. However, their purpose – and their performance in an emergency—are completely different. One is engineered to stop the spread of fire, while the other is designed simply to promote airflow between rooms. Choosing the wrong grille can compromise both compliance and safety.
This guide explains the essential differences, how each grille functions, and why fire door manufacturers must be the ones to supply fire-rated grilles.
What Is a Non-Fire Rated Grille?
A non-fire rated grille is the most common and freely available type of door grille. Its primary goal is airflow, not fire protection.
Key Characteristics of Non-Fire Rated Grilles
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Available in any size and can be sourced from almost any grille manufacturer.
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Designed only to move air from room to room, improving ventilation.
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Usually made from a simple bank of louvres, with no fire-resistant materials.
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Commonly installed in solid core doors, which provide enough strength to support the grille.
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Not recommended for use in hollow core or polycore doors because those cores lack structural integrity.
Where They Are Used
Non-rated grilles are typically found in internal doors where fire resistance is not required – for example, storage rooms, utility areas, or doors simply needing passive airflow.
What Is a Fire Rated Grille?
A fire rated grille looks similar to a non-rated grille at first glance, but its internal construction is completely different. This grille is purpose-built to prevent fire spread through a door opening.
Key Characteristics of Fire Rated Grilles
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Manufactured by a limited number of specialised suppliers.
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Must be tested by the manufacturer in their own tested doorsets to ensure full compliance.
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This means you cannot use any generic fire grille unless it has been specifically tested within that exact doorset configuration.
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Contains an intumescent interlayer that expands when exposed to heat.
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As temperatures rise, the grille fills and seals the opening, blocking fire and smoke from passing through.
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Comes standard with a steel faceplate on both sides for durability and fire performance.
Why Fire Door Manufacturers Must Supply Fire Grilles
Fire doors are tested as a complete system, including the grille, faceplates, core, adhesives, and construction method.
Because the fire grille is part of the certified doorset, only the fire door manufacturer can supply the correct fire-rated grille to ensure:
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full fire-test compliance,
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warranty integrity, and
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legal certification.
Swap the grille – or buy one from an untested source – and the doorset is no longer compliant.
Why Choosing the Right Grille Matters
Installing the wrong grille – especially in a fire door – can compromise:
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building compliance,
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the door’s certified fire rating, and
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the safety of occupants in an emergency.
A non-fire rated grille will not stop smoke or flames. A fire rated grille is engineered to expand and seal the opening, preserving the door’s fire-resistance integrity.
Final Thoughts
While they may look similar, fire rated and non-fire rated grilles serve completely different purposes. If the door is part of a certified fire-resistant system, the grille must also be certified – and only the fire door manufacturer can supply a compliant fire rated grille.
If you need help selecting the right grille for your project, feel free to ask!