Void Mortar Joints: Bane of Brick Masonry

Abstract

The adverse effects of void mortar joints on the performance of masonry are enumerated. Unfilled mortar joints in brick masonry weaken walls, increase leakage, breach a contract, violate the law, and break tradition. The bricklayers union, masonry contractors, architectural and engineering professionals, and materials researchers all agree that unfilled mortar joints should not be permitted. At least since 1890 the literature on masonry has been replete with admonitions on the necessity for filling mortar joints. Masonry may turn out unintentionally bad, but it will never be accidentally good. Inspection of masonry under construction is now required by building codes and specifications promulgated by The Masonry Society, the American Society of Civil Engineers, and the American Concrete Institute (“Specifications” 1988). A method for measuring void joints is described. The unaided human eye is a satisfactory instrument for judging mortar joint solidity. Photographs of typical unfilled joints are shown. The pervasive lack of concern for poor masonry workmanship can lead to undesirable legal consequences.