The legal frame: what the FSO actually says
The Regulatory Reform (Fire Safety) Order 2005 (FSO) places the responsibility for fire safety in non-domestic premises on the “Responsible Person” — usually the employer, building owner, or person in control of the premises. They must ensure fire safety measures, including fire-resisting compartmentation, are maintained in good working order.
Fire doors are part of that compartmentation. A failed fire door means a failed compartment line, which means smoke and fire can spread between zones and stairwells in a fire event. The FSO does not specify how often a fire door must be inspected, but enforcement is risk-based: if a regulator finds a fire door in poor condition, the question they ask is what regime was in place to catch it. Six-monthly is the trade-accepted minimum and the answer most regulators want to hear.
The Building Safety Act 2022 raised the stakes further in higher-risk residential buildings, with quarterly checks now a legal duty in flats over 11 metres. Commercial guidance is following the same direction of travel.
The five common fire door inspection failures
Across UK commercial fire door inspections, the same five items account for the overwhelming majority of failures.
- Intumescent strip damaged or missing. The strip is the foam ribbon set into the door edge or frame — it expands when heated to seal the gap and stop fire spread. Strips get gouged, painted over, or torn off during refurbishment. Replacement is straightforward and matches the original fire rating.
- Smoke seal worn or compressed flat. Often combined with the intumescent strip as a single brush-and-foam unit. Smoke seals are softer and wear faster than the intumescent. Replacement is a 20-minute job per door.
- Fire-rated signage missing or wrong. Fire doors must carry the correct “Fire Door Keep Shut” or “Fire Door Keep Locked Shut” signage. Decorating teams remove them; tenants paint over them; over time they disappear. Cheap to replace, but a definite inspection failure.
- Gap between door and frame exceeds 4mm. Standard tolerance is 2–4mm around the head and jambs, 8–10mm at the threshold. Doors drop over time, frames settle, gaps grow. The fix is hinge adjustment, frame re-fixing, or in rare cases a packer in the rebate.
- Closer does not bring the door fully home against the stop. A fire door must self-close fully from any open position, with the latch engaged. A worn or misadjusted closer that stops short, slams, or fails to latch is a fire compliance failure even if the door itself is in perfect condition.
When repair is enough, when replacement is needed
In our experience, around 85% of fire doors that fail inspection can be brought back to compliance with component-level repair: strip and seal replacement, hinge adjustment, closer service, signage refit. The door blade and frame stay in place.
Replacement becomes necessary when: the door blade itself is structurally damaged (delamination, large impact damage exposing the core), the frame is corroded or structurally compromised, fire-rated glazing has cracked (and the door has glazing as part of its certified set), or the door has been modified beyond what its certification allows (extra ironmongery, repositioned vision panel, drilled-through for cables).
A reputable engineer will tell you honestly which is needed and which is not. Replacement of a fire door is a more invasive job — the frame may need re-skimming or re-decoration after — so it is worth being sure before going there.
How a professional fire door inspection works
A documented fire door inspection covers each door individually. For each, we check and record: door type and fire rating (FD30, FD60, etc.), condition of intumescent strip and smoke seal, gap measurements head/jambs/threshold, hinge fixings and number, closer operation and self-close test, latch engagement test, signage presence and condition, fire-rated glazing where present, hardware compatibility, evidence of unauthorised modifications.
Each door receives a pass/watch/fail rating. Fails are quoted for remedial work, watch items are flagged for the next inspection cycle, passes are documented to confirm compliance.
Common compliance traps we see in the field
Several issues show up repeatedly that buildings managers are surprised by.
- Refurbishment damage. Decorators paint over intumescent strips, builders drill holes through fire doors for cables or hardware, ceiling contractors damage door tops. Every refurbishment programme should include a post-works fire door audit.
- Wedged-open fire doors. The single most common day-to-day breach. Often resolved by fitting magnetic hold-open devices linked to the fire alarm — legal, compliant, and lets the door stay open during normal use.
- Self-closing devices removed. Tenants find closers annoying and remove them. A fire door without a self-closer is not a fire door — the closer is part of the certification.
- Wrong replacement door fitted. Someone replaces a damaged FD30 fire door with an off-the-shelf timber door from a builders’ merchant. The visual match looks fine; the certification is gone.
Documentation: what good looks like
For each fire door in the building, the Responsible Person should be able to produce: original specification or replacement certification, latest inspection record, list of remedial actions taken, schedule for next inspection. This is what a fire safety regulator will ask for, and what an insurer will want to see after any incident.
A proper fire door maintenance contract delivers all of this as standard. The cost of the contract is small relative to the cost of an FSO enforcement action or a voided insurance claim.