Technical Booklet L Combustion Appliances and Fuel Storage Systems·Page 66·4.35
Hearth construction and dimensions
Where a hearth is required, it must comprise at least 12 mm thick non-combustible, non-friable material with edges marked by a change in level. Minimum plan dimensions are shown in Diagram 4.6 with specific measurements for DFE and ILFE fires.
Where a hearth is required, instructions on its minimum plan dimensions are given in Diagrams 4.6 and 4.7. The hearth should comprise of at least a layer of non-combustible, non-friable material not less than 12 mm thick. The edges of the hearth should be marked by a change in level to provide a warning to the building occupants and to discourage combustible floor finishes such as carpet being laid too close to the appliance.
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