This Publicly Available Specification gives guidance on assessing the appearance of facing bricks, and the
determination of on-site measurements of work size dimensions, for all high density (HD) type clay bricks
as defined by BS EN 771-1.
It includes a procedure for comparing sample panels with reference panels in order to assess the
appearance acceptability of consignments of clay facing bricks. It is not intended to apply to common and
engineering HD type clay bricks.
It also provides a method of determining the overall dimensions of all clay bricks. The limits for the
tolerance categories for the mean and range are those that apply to HD type clay bricks where the
manufacturer’s declared work sizes are those traditionally known as British Standard dimensions
(UK standard format clay bricks). If clay bricks are supplied with other work sizes, the limits for these
categories will need to be calculated in accordance with BS EN 771-1.