Our firm designed a reinforced grouted masonry barrier wall on a recent project. During construction, the contractor had several areas that blew out due to pressure from grouting. In some cases, wall sections completely collapsed. But in other cases, the wall just bulged outward between the lateral ties. How much of the wall should the contractor rebuild?
If the wall bulged outward as little as 1/8 inch, the bond between the brick and the mortar has been lost. This will reduce the wall's strength and its resistance to water penetration. Water penetration can be a particular problem if there are voids in the grouted collar joint. For these reasons, blowouts of any magnitude usually are rebuilt. In some cases, however, bed joint bond may not be structurally critical in reinforced masonry. If the structural engineer has determined that this is the case and if it is not aesthetically objectionable, the exterior mortar joints could be repointed to a depth of 3/4 inch to improve water penetration resistance.