The Five Fire Door Failures We Find Most Often — And What They Cost to Fix

Across the hundreds of fire door surveys our team carries out each year, the same five defects appear again and again. Each of them is individually fixable, often quickly and inexpensively. Together, they account for somewhere between 70% and 85% of every “failed” doorset on a typical UK building — which is good news, because it means the apparent scale of most fire door non-compliance reports is usually less daunting than the headline number suggests.

1. Excessive gaps- The most common single failure mode. The gap between leaf and frame on a standard FD30 doorset should generally be 3mm ± 1mm. Anything wider, and the intumescent seal cannot bridge the gap before fire breaks through. The fix is usually a planed-and-rehung leaf, occasionally a new doorset, but rarely catastrophic.
2. Missing, damaged or painted-over intumescent seals- When seals are missing entirely (or have been painted over so thoroughly they will not expand correctly), the doorset’s fire performance drops by orders of magnitude. The fix is a same-day replacement from the original manufacturer’s accessory range.
3. Wrong or worn closers– A fire door that doesn’t fully close is not a fire door. Yet across every building type, we routinely find closers that are too weak, broken, manually disabled, or set incorrectly. Replacement is straightforward and inexpensive.
4. Ironmongery outside the doorset’s tested scope- A door tested with three CE-marked hinges and a certified closer cannot perform reliably if two hinges have been replaced with a non-certified equivalent during a refurbishment. The fix is back-to-original ironmongery — and usually a wider review of who is authorised to specify replacement parts.
5. Missing or wrong signage- The smallest of the five, and the cheapest to fix. “Fire Door — Keep Shut” signage to BS 5499 should appear on every certified fire door, properly positioned, properly mounted, properly visible.

Indicative remedial cost for a typical 50-doorset block, where the failures are spread across the five categories above? Often between £6,000 and £15,000 — well below the cost of full doorset replacement, and dramatically below the regulatory and reputational cost of leaving them unfixed.

The wider lesson is that a fire door inspection report is rarely as catastrophic as it first looks. The right reaction is a calm, technically led remedial schedule — not panic, and not a rush to wholesale replacement.