The tops of all brick walls must be made water-proof, otherwise the rain will soak into the wall heads and ultimately ruin them. When cheap, light coping stones are used, it is necessary to lay a sheet of metal (preferably lead or copper) under them, as shown in Fig. 22. The sheet metal is simply laid on the brickwork and bent over about 1 or 2 inches at each edge. The stones are then bedded in place in the usual manner.

Fig. 22.

Fig. 23.