ABSTRACT
The purpose of cavity walls is to resist rain penetration and to ensure a dry inner leaf, in addition cavity walling provides good thermal insulation, and this may be further improved by using lightweight concrete blocks for the inner leaf of the wall. Concrete
are suitable for general use below D.P.C. However Type ‘B’ blocks, of lower density may be used below ground level D.P.C. for internal walls and the inner leaf of cavity walls.
