When a wall suffers from rising damp owing to the absence of a damp-proof course, the best remedy may be to insert one. The operation is costly, and will be undertaken only when due weight has been given to the expected remaining life of the building and to the possibility of some other palliative treatment providing a tolerable compromise (see Digest no. 41). This Digest describes a method of sawing a slot in a mortar bed joint and inserting a membrane, which will be found much less costly than the usual method. To obtain a satisfactory result, it may be necessary to deal with the soluble salts in the brickwork, as described in Digests nos. 33 and 41.

Replaced by Digest 27 (2nd series).