Technical Booklet L Combustion Appliances and Fuel Storage Systems·Page 45·3.21
Formation of gathers
Open fireplaces require a tapered gather to minimise flue resistance, which can be formed using prefabricated components, corbelled masonry, or a canopy.
To minimise resistance to the proper working of a flue, a tapered gather should be provided in the fireplace for an open fire. This should be formed by –
(a) using prefabricated gather components built into a fireplace recess as shown in Diagram 3.5(a);
(b) the corbelled masonry as shown in Diagram 3.5(b); or
(c) using a suitable canopy, as shown in Diagram 3.6.
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