CAREFUL DESIGN IS IMPORTANT

Press, Volume CVI, Issue 31349, 20 April 1967, Page 24

CAREFUL DESIGN IS IMPORTANT

Fireplaces and chimneys should be carefully designed and built to guard against fire hazards. Hearths should be composed of reinforced concrete supporting slab with brick or tile surface or a reinforced brick slab.

The floor and joist should be cut back to the face of the front hearth and should not be used as boxing for the hearth slab. Combustible material should not be placed within nine inches of the fireplace opening and the front hearth should extend a minimum of 12in either side of the opening. All timber work should be kept a clear distance of 2in from the chimney. Some provisions in the United States permit one inch if the space is filled with incombustible insulating material. There is probably sound reason for reducing the two inch requirement to one inch where the chimney is on an outside wall. The use of full bed and head joints in all brickwork is essential.

Many fire surrounds of precast concrete tile faces are used with all types of fireplaces and chimneys. Such surrounds should have a one inch rebate over the opening. The lintel if either of precast or cast-in-situ concrete should have a corresponding rebate made so that the two fit tightly in place. This eliminates the possibility of flame or heat igniting the timber framing above the chimney breast All surrounds should have ties to fasten them to either the chimney or timber framing adjoining the chimney. There should be at least two ties across the top of the surround and two at each side to keep the surround from moving away from its bedding.