Section 41(3) in West Bengal Municipal (Building) Rules, 2007
(3)The following material shall, for the purposes of this rule, be deemed to be incombustible :(a)brick-work constructed of bricks, well-burnt, hard and sound, properly bounded and solidly put together with(i)mortar compounded of lime and sharp clean sand, hard clean broken brick, broken flint, grills or slag, well pulverised, or(ii)cement mixed with any of the materials mentioned in sub-clause (i);(b)granite or other stone which is suitable for building purposes by reasons of its solidity and durability;(c)slate, tiles, bricks and terracotta, when used for coverings or corbels;(d)flag-stones when used for floors over arches, if not exposed on the underside and if not supported at the ends only;(e)concrete, composed of broken brick, stone chippings or selected slag and lime, cement or calcined gypsum, when the concrete is used for filling in between joists of floors to a depth of not less than ten centimetres;(f)any combination of concrete, steel or iron or any other materials approved in this behalf from time to time by the Board of Councillors.Explanation. In this rule, the expression brick, lime or cement shall mean respectively such brick, lime or cement as conform to the standard and quality specified in this behalf in the latest edition of the National Building Code.
