Copyright Goodheart-Willcox Co., Inc. 250 Section 4 Techniques 12.4.1 Corbeling a 12″ Wall Corbeling is a method used to widen a wall by project- ing out masonry units to form a ledge or shelf. When building a corbel, each brick course extends out farther than the one below it. See Figure 12-65. Because corbels normally support a load, they must be carefully constructed. Headers are generally used to tie a corbel into the base. Building codes generally require the top course to be a full header course. All joints must be completely filled with mortar. The following procedure is suggested for corbeling a 12″ wall. See Figure 12-66. Code Note Corbel Projection The maximum projection of one unit shall not exceed one-half the height of the unit or one-third the thickness of the unit at right angles to the wall. P R O C E D U R E Corbeling a 12″ Wall 1. Snap a line on the foundation or base where the front edge of the wall is to be constructed. Also, mark the starting and ending points of the corbel on the foundation or base. 2. Lay out the first course as a dry course to check spacing. Running bond will be used with a header course every seventh course. 3. Lay the first course with headers on the front wythe and stretchers on the back. Use a full mortar bed. Level, plumb, and square the brick. Check the spacing. 4. Lay the second through sixth courses. Check the height of each course as it is laid and be sure bed joints are uniform and level. Brick bearing wall Reinf., as req’d Flashing Weep holes 24 in. (600 mm) O.C. max. Interior finish Furring anchor Furring with insulation Finish floor Slab on grade Vapor retarder Brick Industry Association Figure 12-64. Weep holes and flashing are necessary in exterior single wythe masonry walls to reduce moisture penetration. Timothy L. Andera Figure 12-65. Each course has been corbeled out from the previous one to eventually create a shelf to support the three-sided bay window. The last regular course has been cut to height to accommodate the brick sill. The brick sill is sloped to ensure adequate drainage. The brick sill hangs over the lower course to create a drip edge. Header course Corbeling Each course is set out ¾uni2033 Goodheart-Willcox Publisher Figure 12-66. Procedure for corbeling a 12″ brick wall.