Technical Booklet L Combustion Appliances and Fuel Storage Systems·Page 27·2.25
Wall thickness for masonry and flue block chimneys
The thickness of walls for masonry chimneys around the flue (excluding any flue liner thickness) must comply with the minimum dimensions shown in Diagram 2.4, which specifies 100 mm or 200 mm depending on location and compartment adjacency.
The thickness of the walls for a masonry chimney around the flue, excluding the thickness of any flue liner, should be in accordance with Diagram 2.4.
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