Fire doors are one of the most important parts of a building’s passive fire protection system, but they’re often overlooked until an inspection highlights a problem. Even a well-made fire door can fail if it’s damaged, poorly maintained or fitted with the wrong components.

At MD Fire, our experienced engineers provide professional fire door inspections, maintenance and installation for landlords, facilities managers and business owners across London, Surrey and the Home Counties. We help clients maintain compliant, well-maintained fire doors that provide vital protection for people and property in the event of a fire. Whether you need routine inspections, repairs or new fire door installations, we deliver reliable, high-quality workmanship tailored to your building and legal responsibilities.

Based on our experience here are some of the most common reasons why fire doors fail inspection and what can be done to put them right.

1. Excessive gaps around the door

One of the most frequent issues inspectors find is incorrect gaps between the door and the frame. Ideally, the gap around the top and sides should be between 2-4mm, while the gap beneath the door should comply with the manufacturer’s specification and relevant fire door standards. If these gaps are too wide, smoke and flames can spread much more quickly during a fire. Small changes caused by wear, movement within the building or poor installation can all affect these gaps over time, which is why regular inspections are so important.

2. Damaged or missing intumescent seals

Intumescent seals are designed to expand when exposed to heat, helping to seal gaps around the door during a fire. If they’re damaged, painted over, loose or missing altogether, the fire door may no longer provide its certified level of protection. These seals can become worn through everyday use, particularly in busy commercial buildings and apartment blocks.

3. The self-closing device isn’t working properly

A fire door can only do its job if it closes fully after someone passes through it. Faulty self-closing devices, disconnected arms or doors that have been wedged open are all common reasons for failed inspections. If the door doesn’t shut and latch correctly on its own, it may not contain fire and smoke when it’s needed most. Where a fire door needs to be held open for operational reasons, an approved solution such as a Dorgard may be appropriate, provided it’s compatible with the fire door and correctly installed and maintained. This allows the door to remain open during normal use while ensuring it closes automatically when the fire alarm is activated.

4. Incorrect or damaged hinges

Fire doors require the correct fire-rated hinges to perform as intended. Loose screws, worn hinges or unsuitable replacements can affect the way the door operates and may prevent it from closing correctly. Inspectors will always check that hinges remain secure and suitable for the specific fire door.

5. Unauthorised alterations

It’s not unusual to find fire doors that have been modified after installation. Cutting down the door, fitting non-approved letterboxes, drilling holes for cables or replacing hardware with non-fire-rated products can all invalidate the door’s certification. Even seemingly minor alterations can significantly reduce fire resistance, so it’s always best to leave repairs, adjustments and upgrades to qualified fire door specialists who understand the relevant standards and manufacturer requirements.

6. Damaged door leaves or frames

Daily use can take its toll, particularly in schools, offices, shops and apartment buildings where doors experience constant traffic. Cracks, warping, impact damage or deterioration to the door leaf or frame may all affect the door’s ability to resist the spread of fire and smoke. While some defects can be repaired, more serious structural damage may require replacement.

7. Glazing that’s no longer compliant

Many fire doors include vision panels, but these must use certified fire-resistant glazing that’s installed correctly. Loose glazing beads, damaged glass or unauthorised replacements can all result in a failed inspection because they compromise the door’s tested fire performance.

8. Missing or unsuitable ironmongery

Every component on a fire door matters. Locks, latches, handles, closers and other ironmongery should all be fire-rated and compatible with the door set. Replacing damaged hardware with standard products may seem like a simple repair, but it can leave the entire door non-compliant.

9. Poor maintenance

Fire doors are often installed correctly but gradually fall into disrepair because they’re rarely inspected. Routine maintenance helps identify small issues before they become major compliance problems, reducing the risk of costly repairs or complete door replacements.

10. Lack of regular fire door inspections

Fire doors should be inspected regularly to ensure they remain in good working order. In many commercial and multi-occupied residential buildings, a professional inspection every six months is considered good practice, while fire doors in high-use areas may need checking every three months. Routine visual checks between formal inspections can also help identify damaged seals, loose hinges, glazing issues or doors that no longer close correctly. The responsibility for ensuring fire doors are inspected and maintained usually falls to the building’s Responsible Person. This may include a landlord, facilities manager, managing agent, employer or building owner, depending on who has control of the premises. Arranging regular inspections by a competent fire door specialist helps maintain compliance and gives you peace of mind.

Need professional fire door services in London and the Home Counties?

Whether you require fire door inspections, maintenance or new installations, MD Fire is here to help. Our experienced engineers provide reliable fire door services for commercial and residential properties across London, Surrey and the Home Counties. As a BAFE-approved, NICEIC-registered and TrustMark-accredited company, we’re committed to delivering the highest standards of workmanship, safety and compliance.

Contact our team today to arrange a fire door inspection or fire risk assessment on 020 8265 2061.