# The Local Authorities' Cemeteries Order 1977, Paragraph 6


Within 24 hours of any burial in a walled grave or vault, the coffin shall be—
(a) embedded in concrete, and covered with a layer of concrete not less than six inches thick; or
(b) enclosed in a separate cell or compartment of brick, slate, stone flagging or precast concrete slabs of a 1:2:4 mix, in any case not less than two inches thick, in such a manner as to prevent, as far as may be practicable, the escape of any noxious gas from the interior of the cell or compartment.

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Source: https://www.legislation.gov.uk/uksi/1977/204/schedule/2/part/I/paragraph/6 (the official version)
Page: https://openlegislation.uk/local-authorities-cemeteries-order-1977/schedule-2/part-I/paragraph-6
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.