I recently fitted a replacement fire door in my mother’s flat and had it inspected by a certified engineer. He emphasised that precise dimensions are critical: the door was 762 × 1981 × 44 mm (FD30), with perimeter gaps strictly between 2–4 mm. Anything outside this tolerance, or using a thinner 38 mm leaf, renders the door non-compliant and ineffective.
Could anyone recommend a straightforward, reliable Natural SHEV Guide for smoke ventilation systems?