Fire Door Certificate London — from £129.99

Gap tolerances

The gaps around the door edges must not exceed 3–4mm. Gaps that are too large allow smoke and flame to pass through before the intumescent seal activates. Gaps that are too small prevent the door from closing properly.

Intumescent seals

Intumescent strips are fitted around the door edge and expand rapidly when exposed to heat, sealing the gap and preventing fire spread. Inspectors check they are present on all four sides, undamaged, and correctly fitted into the rebate.

Cold smoke seals

Brush or compression seals that prevent cold smoke from passing around the door at normal temperatures — before the fire is hot enough to activate the intumescent seal. Required for FD30S and FD60S rated doors.

Self-closing device

All fire doors must self-close and latch every time — without being held open manually. The closer is tested for correct tension, speed, and full closure from 90 degrees and from a partially open position. A door that does not latch provides no fire protection.

Fire resistance rating

The inspector checks the door leaf and frame for rating markings (FD30 or FD60) and assesses whether the rating matches the requirement for that location. FD30 = 30 minutes fire resistance. FD60 = 60 minutes fire resistance.

Door furniture and hinges

Hinges must be fire-rated (typically 3 × 76mm ball-bearing hinges), handles must not obstruct closing, and any letterboxes or cat flaps that have been retrofitted must be fire-rated.

Glazing panels

Any glass panels in the door must be fire-rated glazing — not standard glass. Standard glass shatters in seconds under fire conditions. Fire-rated glazing maintains integrity for the rated period.

Signage and condition

"Fire Door — Keep Shut" signage must be present on both sides of all fire doors on escape routes. The door leaf, frame, and surrounding wall must show no signs of damage, modification, or deterioration that could compromise performance.

Missing or damaged intumescent strips (most common)

Found in roughly 60% of older properties. Strips deteriorate over time, are sometimes removed during repainting, or were never fitted to the correct standard. A missing intumescent strip means the door provides no effective fire resistance regardless of its rated construction.

Self-closer not working correctly

Self-closers seize up, lose tension, or are deliberately disabled by occupants who find them inconvenient. A fire door propped open or failing to latch is legally equivalent to having no fire door at all.

Excessive gaps around the door

Common in older properties where frames have moved or settled over time. Gaps exceeding 4mm allow smoke and hot gases through before the intumescent seal can activate.

Non-fire-rated glazing

Many older fire doors have had standard glass panels installed as replacements. Standard glass shatters within seconds of fire exposure — providing no protection and creating a significant hazard from flying glass.

Missing cold smoke seals

Required on all FD30S and FD60S doors. Often absent on older doors or removed during maintenance. Without cold smoke seals, occupants can be overcome by smoke before the fire reaches the door.

Door wedged or propped open

The single most dangerous and most common finding. Occupants wedge fire doors open for convenience, completely negating their purpose. This is a legal breach and in the event of a fire creates a direct channel for smoke and flame to travel through the escape route.