The walls where eroded at the ground level are to be underpinned with
hard-burned brick, laid in good cement mortar and extending to a depth
of at least 12 inches below the original ground level. This work must be
carried on gradually and very carefully in conjunction with the clearing
out of the débris. The under surfaces of the overhanging walls must be
carefully trimmed to afford solid horizontal bearings against the
brickwork. The face of the brickwork is to be set back at least 1 inch
and not more than 2 inches from the face of the wall, and the brickwork
is to be plastered with a coating of cement mortar, 1 to 2 inches thick,
bringing it out flush with the outer wall.