The wall comprises a number of similar wall sections joined together and to the floor and ceiling. One or more of the sections (3) are secured to floor and ceiling by clamps (4, 5), and they are shaped so as to engage positively together. The shape is such as to give a pattern of ribs at fixed intervals. One or more adaptor pieces are provided, their non-profiled portions partly overlapping the adjacent wall sections. Each clamp can be formed by an S-shaped spring clip, one fitting over a vertical edge on floor or ceiling and the other over a wall section.