ABSTRACT
No combustible material, other than timber fillets supporting the edges of a hearth where it adjoins a floor, shall be placed under a constructional hearth serving a Class 1 appliance
less than 500mm. Where the thickness of solid non-combustible material surround a flue in a chimney
serving a Class 1 appliance is less than 200mm, no combustible material, other than a floorboard, skirting board, dado rail, picture rail, mantle-shelf or architrave, shall be so placed as to be nearer than 40mm to the outer surface of the chimney (Approved Document J Part C).
