In Detail
Materials, methods and the situations they suit
Most fire door failures at audit are maintenance failures, not installation failures — the door was fine on the day it was fitted and has degraded since. Below is the level of detail we work to on every maintenance visit across Merseyside, and the parts of a fire door that most commonly need attention.
Intumescent and smoke seals — the most common failure
Intumescent strips expand above ~200°C to seal the gap between leaf and frame. Smoke seals (brush or fin) block cold smoke before the fire takes hold. They fail by shrinkage, paint contamination, mechanical damage from ironmongery changes, and degradation over a 10–15 year service life. We replace continuous lengths around head and jambs (not just packed sections at the latch), match the original profile and grade, and re-route into existing rebates so the leaf still closes onto a flush face.
Overhead closers — adjustment, replacement and grading
Grade-13 closers degrade by losing hydraulic damping or spring tension. Symptom: door slams, door doesn't latch from half-open, or closer leaks oil. We adjust closing speed and latching action where possible, replace the unit where not, and re-grade to match the door's weight and width — a Grade 3 closer on a 1000mm leaf is a frequent finding and a guaranteed audit fail.
Hinges, latches and ironmongery
CE-marked hinges (minimum 3 per leaf on a heavy fire door), with intumescent hinge pads where the data sheet requires. We replace hinges that have dropped or worn, refit hinge bolts where they've been removed, and realign latches that are catching. Where a leaf has dropped we ease the linings and re-set the hinge housings rather than packing the leaf — packing changes the gap geometry and the FD rating.
Gap tolerances and threshold integrity
Fire doors require gaps of 2–4mm at head and jambs and 8–10mm at threshold (or as the data sheet specifies). Doors drift outside tolerance through frame movement, leaf warp and floor build-up from new carpets. We measure with a feeler gauge, adjust hinge positions or plane edges within the leaf's tested limits, and replace threshold seals or drop-down smoke seals where the gap is excessive.
Signage and final inspection
'Fire Door — Keep Shut' signage must be present on both faces of every fire door under BS 5499. Missing or peeling signage is a quick audit fail — we replace where needed. Final inspection on every visit confirms positive latching, free swing, intact seals, certified ironmongery and complete signage. The visit isn't closed until the door operates correctly.
