Masonry Magazine April 2006 Page. 45
Lipped brick, also called shelf brick and rabbeted brick, are typically used at shelf angles and steel lintels to hide the steel from view. In some cases, a rather large horizontal expansion joint may be necessary to allow for movement, and the resulting sealant joint can be sizable and visually unappealing. To reduce the apparent size of the joint, a lipped brick can be used to cover the toe of the angle. Typical dimensions of lipped brick are shown in Figure 1. The manufacturer should be consulted to determine the dimensions of a lipped brick.
Manufacturing Lipped Brick
LIPPED BRICK can be manufactured using either the extrusion process or the molding process. Molded lipped brick can be produced by either using a mold box with a lip form set in it or by saw cutting the shape from a regular brick. Saw cutting is more common for molded brick. When lipped brick are produced by the extrusion method, the direction of extrusion with respect to the projecting lip must be considered. A lipped stretcher can only be produced by extrusion if the unit is produced by end extrusion and is end cut. Units produced by extrusion with the bed surface perpendicular to the direction of extrusion must be cut to a rectangular shape before the lip can be formed. The lip is then hand cut. The latter is the most common method of manufacturing extruded lipped brick. The lip can be formed before or after the brick is fired. Either technique is acceptable. If formed after firing, the lip is always cut with a masonry saw. Neither method will impair the integrity or strength of the brick or increase its susceptibility to water penetration.
Site Cutting Lipped Brick
In situations when lipped brick are not manufactured for a job, the mason may cut the lipped brick at the site. Extreme care should be taken to ensure the proper size is achieved, and the cut brick should be subject to close scrutiny. Oversawing may cause the lip to be fragile. On the other hand, if the lip is too wide there may not be adequate room for bearing on the shelf angle.