Fire Door Requirements for London HMO Landlords: FD30, Certification, and Inspection

Which Doors Need to Be Fire Doors in an HMO?

In an HMO, fire doors (rated to FD30 — 30 minutes fire resistance) are required at several key locations. Every bedroom door must be a fire door. The kitchen door must be a fire door. In larger HMOs, fire doors may also be required at the entrance to each flat or lettable unit within the building, and at any door opening onto the protected staircase. In practice, every door on the escape route in an HMO should be a fire door unless a specific risk assessment concludes that a non-fire-rated door is acceptable in that location.

The protected staircase is the key concept in HMO fire safety. In most London Victorian terraces let as HMOs, the staircase is the only means of escape from upper floors. Providing a protected staircase — enclosing it with fire-resisting walls and self-closing fire doors that keep smoke out for long enough for all occupants to escape — is the primary fire safety measure in these buildings. Every door from a habitable room into the staircase enclosure must be FD30.

What Is FD30?

FD30 is the designation for a fire door that has been tested to provide 30 minutes of resistance to fire. The "FD" stands for Fire Door; the "30" is the time in minutes. Fire door sets are tested to BS 476 Part 22 (the older British Standard still commonly referenced) or to the European standard BS EN 1634-1. The test subjects the complete door set — door leaf, frame, intumescent strip, and ironmongery — to a standardised fire test. A door tested and certified under these standards will have a third-party certification mark confirming its performance.

A fire door without a certification label is not a compliant fire door regardless of its apparent construction or thickness. Fire door inspectors and local authority HMO officers will check for certification marks. The Certifire, BWF-Certifire, and BM TRADA Q-Mark certification schemes are the most commonly specified. The certification label is typically found on the top or side edge of the door leaf, or sometimes on the hinge side of the frame.

Intumescent Strips and Smoke Seals

A fire door without intumescent strips provides no meaningful protection. Intumescent strips are fitted within the door leaf or the frame (or both) and expand under heat to seal the gap between the door and the frame, preventing the passage of flames and hot gases. They are activated at around 150 to 200 degrees Celsius — well below a structural fire temperature. Without intumescent strips, the gaps around the door provide a direct path for smoke and flame well within the FD30 test window.

Cold smoke seals are separate to intumescent strips and provide protection against the passage of cold smoke (smoke at ambient temperature) before the intumescent strips have activated. Cold smoke is the primary killer in most residential fires — occupants are overcome by smoke before flames reach them. Cold smoke seals are typically brush seals fitted to the door leaf or frame. In HMOs, FD30S doors (with cold smoke seals) are recommended, and some local authorities require them specifically.

Gap Tolerances

The maximum permitted gaps for a compliant fire door installation are 3mm at the sides and top (the "stile and head" gaps) and 8mm at the bottom (the "floor gap"). These tolerances apply to a closed door in the normal installed position. Gaps in excess of these tolerances compromise the fire resistance of the installation. A common finding in HMO inspections is that fire doors have been fitted with excessive gaps — sometimes because the original frame has racked slightly, or because the door has been trimmed to fit without adjusting the intumescent strips accordingly.

Self-Closing Devices

Every fire door in an HMO must be fitted with a self-closing device — typically a hydraulic overhead door closer — that reliably returns the door to the closed position from any open angle. A fire door held permanently open by a wedge or doorstop provides no protection at all. Door closers deteriorate with age and regular use, and should be checked as part of any fire door inspection. A closer that allows the door to close slowly but fails to latch is a common finding — the door must close and latch fully to provide its rated fire resistance.

Acoustic hold-open devices (devices that release automatically when a fire alarm activates) are acceptable for common-area fire doors such as staircase lobby doors that would otherwise impede movement through the building. These devices must be connected to the fire alarm system and must fail-safe to the closed position on power failure.

Fire Door Inspection and Maintenance

Fire doors should be inspected by a competent person every six months as part of the HMO maintenance programme, and immediately after any damage or impact. The inspection should cover: the certification mark and condition of the door leaf and frame; the intumescent strips and smoke seals for continuity and condition; the self-closer for function and adjustment; the gap tolerances on all four sides; the ironmongery (hinges, latch, lock) for function; and the overall condition of the door surface for signs of damage that could compromise fire resistance. A written record of each inspection should be maintained in the fire safety log book.