What is the proper spacing for contraction/expansion joints in portland cement plaster/stucco applications?
The proper use of contraction joints in stucco systems will depend on a number of variables, including: the type of construction materials to which the stucco will be applied; the orientation of the construction—vertical (walls) or horizontal (ceilings); and whether the surface is curved or angular. Stucco may be direct-applied to concrete or masonry substrates; however, if these materials are used together, as in the case of a concrete framework of beams and columns with masonry block infill, a joint may be required at the transition of one material to another. Stucco that is direct-applied to concrete or masonry requires contraction joints only where there is a change in material or where there are joints in the concrete or masonry structure. Metal lath may be used over concrete or masonry construction and should be used in sheathed frame and open frame construction. When stucco is applied to any construction using metal lath, joint spacing recommendations should be implemented. The
