Copyright Goodheart-Willcox Co., Inc. Chapter 12 Laying Brick 229 of the triangle. Hold the second tape at the 3′ mark on the chalk line on the concrete. Position tape measures to create a triangle so the two tapes intersect at 4′ and 5′. Mark the concrete at the intersecting inside edges of the two tapes at 4′ and 5′. This will identify the top part of the triangle. Position one end of the chalk box over the mark on concrete, representing the outside corner of the brick wall. The other end of the chalk box should be run past the mark where the intersection of 4′ and 5′ occurred. Snap the line. This line will be the sec- ond line of the 3-4-5 triangle. Figure 12-18 shows that the three tape measures have been laid out to demon- strate the 3-4-5 triangle. Using the 3-4-5 method cre- ates a perfect right angle as represented by the framing square next to the tape measures. See Figure 12-19. If larger distances are needed, multiples of 3′, 4′, and 5′ can be used. 12.2.4 Using a Corner Pole and Gauge Stick A corner pole, sometimes referred to as a story pole, is a narrow board that is generally 1″ × 2″ and 8′–10′ long (about one story in height). A corner pole is used to measure the mortar joint heights of each course of masonry. See Figure 12-20. Each joint is marked on three sides of the board (pole), as well as window heights, door heights, sill heights, or any other fea- ture that needs reference. A corner pole saves time when building corner leads by determining individual course heights. Some jobs require more than one corner pole because different materials are used or because features such as windows and doors are at different elevations. A bench mark (nail or other permanent object) is generally used to ensure proper placement of the corner pole with respect to the building elevation. It is always positioned at that point for measurements. A gauge stick is similar to a corner pole, but has the advantage of being shorter and less bulky, measur- ing about 4′ long and 3/4″ square. A gauge stick helps masons to lay all brick courses in uniform bed joints. Gauges are generally marked in terms of four brick courses. For example, an 11″ gauge would require 1/2″ bed joints for 2 1/4″ high brick (4 bricks × 2 1/4″ + 4 mortar joints × 1/2″ each = 11″). Masons also use a 6′ mason’s folding rule to maintain proper course spacing. Author’s image taken at Job Corps, Denison, IA Figure 12-18. The three tape measures have been laid out to demonstrate the 3-4-5 triangle. Author’s image taken at Job Corps, Denison, IA Figure 12-19. Using the 3-4-5 method creates a perfect right angle as represented by the framing square next to the tape measures. Corner pole Goodheart-Willcox Publisher Figure 12-20. Corner pole being used to set the height for the first brick in each course of the corner lead.