Common Failures Found in Fire Door Inspections (and How to Fix Them)

Fire doors are among the most misunderstood elements of a building’s fire safety strategy. To the casual observer they look like any other door, but in reality, they’re engineered barriers designed to hold back fire and smoke long enough for people to escape and for fire services to respond.

The problem is that inspections repeatedly uncover the same set of failings. Some are due to poor installation. Others stem from lack of maintenance or simple neglect. Left unresolved, these issues compromise compartmentation and can turn an expensive doorset into a liability.

Below, we explore the most common failures found in fire door inspections — why they matter, and how they should be fixed.

1. Excessive Gaps Around the Door

One of the most frequent and dangerous defects is incorrect clearances between the door leaf and the frame. Fire doors are designed to work with precise tolerances — typically 3–4mm. Anything wider and smoke will exploit the gap long before flames breach the door. Anything tighter, and the door may not close properly.

Inspectors often find uneven gaps along the head or stiles, sometimes due to warped frames or poorly hung doors. These seemingly small discrepancies can dramatically reduce fire resistance.

How to Fix:

• Measure gaps consistently with calibrated tools, not by eye.

• Adjust or re-hang the door where possible.

• Replace warped or defective frames if adjustments can’t achieve compliance.

• Always confirm the corrected gaps align with the manufacturer’s specifications.

2. Damaged or Missing Intumescent Seals

Intumescent and smoke seals are critical. Under heat, intumescent strips expand to close the gap between door and frame, while brush or blade smoke seals prevent cold smoke leakage in the early stages of a fire.

Common failures include seals painted over, split, loose, or entirely missing. In some cases, the wrong type of seal has been installed — for example, intumescent only, without smoke seals where required.

Why It Matters:

Without functioning seals, even a correctly hung door loses its rating. Smoke and toxic gases pass through unchecked, putting escape routes at risk.

How to Fix:

• Replace damaged or missing seals immediately with products of the correct type, size, and rating.

• Ensure seals are continuous around the full perimeter of the door leaf or frame.

• Never paint over seals — it prevents them from expanding.

3. Faulty or Missing Door Closers

A fire door is useless if it doesn’t close. Inspectors frequently find doors propped open, closers disconnected, or units so weak they fail to latch. In some cases, closers have been maladjusted to prevent “slamming” — but this means the door doesn’t engage properly with the frame.

Why It Matters:

During a fire, even a small delay in closing leaves the compartment unprotected. The door’s performance is measured with it closed, not ajar.

How to Fix:

• Every fire door should have a tested, appropriately sized closer fitted.

• Adjust closing speeds so the door latches firmly but without violent slamming.

• For areas requiring regular access, consider hold-open devices linked to the fire alarm system rather than disabling closers.

4. Non-Fire Rated or Damaged Glazing

Vision panels and glazing units are common weak points. Inspections often reveal cracked glass, damaged beading, or replacements using standard (non-fire-rated) glazing. In a fire, ordinary glass fails rapidly — undermining the integrity of the entire doorset.

How to Fix:

• Only use glazing systems that have been fire-tested with the door type.

• Replace damaged panels with certified equivalents.

• Ensure glazing beads and seals are intact and properly fixed.

5. Incorrect or Inadequate Ironmongery

Handles, locks, hinges, and other hardware must be fire-rated. A compliant fire door requires at least three CE/UKCA-marked hinges, correctly fixed with all screws in place. Inspectors frequently find missing screws, loose fixings, or hardware substituted without certification.

Why It Matters:

The door leaf is only as strong as its connections. In fire conditions, untested or poorly fixed ironmongery can fail quickly, allowing the door to collapse.

How to Fix:

• Fit only fire-rated ironmongery recommended for the specific doorset.

• Ensure hinges, locks, and handles are installed with the correct number and type of screws.

• Fit intumescent pads under hinges and locks where required by test evidence.

6. Door Leaf or Frame Damage

Everyday use takes its toll. Doors are battered by trolleys, furniture, and daily traffic. Inspectors regularly find deep gouges, cracked veneers, warped leaves, or frames separating from the wall.

Why It Matters:

Structural damage compromises the ability of the door to resist heat and maintain integrity. Even small defects can grow under fire conditions.

How to Fix:

• Minor surface damage may be repairable with manufacturer-approved materials.

• Structural or frame damage usually requires replacement.

• Protect vulnerable areas with kick plates or guards to prevent repeat damage.

7. Inadequate Signage and Misuse

Signage is often missing, faded, or replaced with incorrect labels. More worrying is how frequently fire doors are misused — propped open with wedges, bins, or even fire extinguishers.

Why It Matters:

A propped-open fire door cannot save lives. In many cases, fire investigations show that open doors directly contributed to smoke spread and fatalities.

How to Fix:

• Fit mandatory “Fire Door Keep Shut” or “Keep Locked” signage on every leaf.

• Educate building users on the dangers of wedging doors.

• Install compliant hold-open devices where necessary for accessibility.

The Bigger Picture: Inspection and Responsibility

The same failures appear again and again, across sectors and building types. The reasons are simple: poor installation, lack of maintenance, and insufficient awareness. Yet every one of these faults is preventable.

Regular inspections by competent professionals ensure fire doors perform as intended. But inspections alone are not enough — defects must be rectified promptly, using correct materials and accredited installers.

Fire doors should never be treated as “fit and forget.” They are active life-safety systems, as vital as alarms or sprinklers.

Conclusion

The truth is simple: most fire door failures are not dramatic, they’re mundane. A missing screw, a painted-over seal, a door propped open with a chair. But these small failings add up to catastrophic risk.

By investing in regular inspection, immediate repair, and proper education, building owners can ensure their fire doors remain what they were designed to be: barriers that protect lives when they’re needed most.

At JW Simpkin, we inspect, maintain, and install fire doors to the highest standards — ensuring every last detail, down to the millimetre, is correct. Because in fire safety, detail is everything.