Common Fire Door Defects Found During Inspections

Fire doors can only protect lives if they are in proper working condition. Here are the most common defects our inspectors find and why each one matters.

Damaged or Missing Intumescent Strips

Intumescent strips are fitted within the door or frame and expand when exposed to heat, sealing the gap between the door and frame to prevent fire and smoke from passing through. Common issues include strips that have been painted over (preventing expansion), strips that are missing entirely (often after maintenance work), and strips that have been damaged or are deteriorating with age.

Faulty Self-Closing Devices

Every fire door must be fitted with a self-closing device that pulls the door fully shut from any open position. We frequently find closers that have been adjusted to reduce closing force (making the door easier to open but preventing it from latching properly), closers that have been removed or disconnected, doors propped open with wedges or other objects, and worn-out closers that no longer have sufficient force to latch the door.

Excessive Gaps

The gap between a fire door and its frame should not exceed 3mm when the door is closed (except at the threshold, where up to 8mm may be acceptable). Gaps larger than this allow fire and smoke to pass through, defeating the door's purpose. Gaps develop due to building settlement, hinge wear, door warping, and improper fitting.

Damage to the Door Leaf

Fire doors are constructed with specific fire-resistant materials. Any damage to the door leaf — holes, deep scratches, delamination, or patches — can compromise its fire resistance. Even seemingly minor damage like a drilled hole for a spy viewer that was never installed creates a weak point.

Incorrect Hardware

All hardware fitted to a fire door (locks, handles, hinges, letter plates) must be tested and certified as compatible with the door's fire rating. Non-fire-rated hardware can create weak points that allow fire to penetrate the door assembly.