Section 41(3)(a) in West Bengal Municipal (Building) Rules, 2007
(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);