Technical Booklet D Structure·Page 81·4C.38
Tolerance for modular brick and block dimensions
Wall thicknesses derived from brick or block dimensions may be reduced by the permitted deviation from work size specified in the relevant British Standard for bricks or blocks of the same material.
Where a wall is constructed of bricks or blocks having modular dimensions derived from BS 6750, the wall thicknesses prescribed in this Part which derive from a dimension of a brick or block may be reduced by an amount not exceeding the deviation from work size permitted by a British Standard relating to equivalent sized bricks or blocks made of the same material.
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