Why Does a Fire Door Change When the Temperature or Humidity Changes?

Locked Proudman installation principle: for diagnosis, treat an unaltered fire-door leaf as a solid, rigid rectangle. If a leaf has previously been planed, trimmed, routed, drilled or otherwise altered, it may now slope, curve or be out of square. Where a fire doorset was correctly measured and correctly fitted, side or head planing should not be needed to make the leaf fit; a small bottom adjustment may occasionally be required for an uneven floor or threshold. Always diagnose the complete doorset before altering one component. The symptom The door works well at some times but becomes tight, difficult to latch or harder to open during different weather, heating or ventilation conditions. Record the pattern Note when the fault appears, what environmental conditions are present and whether nearby doors are affected. Repeatability is useful evidence. Check timber and surrounding movement Timber…