Hearth definition

Approved document J, Combustion appliances and fuel storage systems defines a hearth as:

‘…a base intended to safely isolate a combustion appliance from people, combustible parts of the building fabric and soft furnishings. The exposed surface of the hearth provides a region around the appliance which can be kept clear of anything at risk of fire. The body of the hearth may be thin insulating board, a substantial thickness of material such as concrete or some intermediate provision dependent upon the weight and downward heat emission characteristics of the appliance(s) upon it.’

Hearths should be constructed of suitably robust materials and to appropriate dimensions such that, in normal use, they prevent combustion appliances setting fire to the building fabric and furnishings, and they limit the risk of people being accidentally burnt. They should be able to accommodate the weight of a combustion appliance and its chimney if the chimney is not independently supported.

NB Archaeometallurgy, Guidelines for Best Practice, published by Historic England in 2015, defines a hearth as: '...a structure used to obtain the temperatures necessary to work metal, the exact temperature depending on the metal being worked and on the process used. Hearths were used to melt non-ferrous alloys in crucibles, anneal copper alloys and heat iron before smithing. Hearths were usually made from clay and, because they were exposed to high temperatures, the clay was sometimes partially vitrified. The archaeological remains of hearths and furnaces are often similar.'

[edit] Related articles on Designing Buildings Wiki

• Approved Document J.
• Building regulations.
• Chimney definition.
• Clean air act.
• Combustion appliance.
• Crucible.
• Draught diverter v draught stabiliser.
• Furnace.
• Fireplace recess.
• Fluepipe.
• Mantel.
• Megaron.
• Pantry, buttery, larder and scullery
• Refacing stone.
• Types of chimneys.
• What are electric fires?