Copyright Goodheart-Willcox Co., Inc. Chapter 3 Tools and Equipment 31 Measuring scales found on the back side of mason’s rules include standard US customary, standard brick spacing, oversized brick spacing, and modular spac- ing. As an example of measurement, the numbers from 1 to 0 on the brick ruler represent the height of various brick and mortar joints when being laid to that scale. For example, if the average measurement of bricks to be used is 2 1/16″ and the desired width of the mor- tar joint selected measures of 7/16″, then the total brick and joint measurement is 2 1/2″. While holding your thumbnail on the edge of the rule at 2 1/2″, turn the rule over in your hand, and the corresponding num- ber on the back side of a standard brick rule would be the number 2 in black text. The 2 represents the scale to follow for this brick layout, which is “scale 2.” The col- ored number in red on the same line tells the specific brick course. Since this is the first course, the red num- ber in this instance would be 1. To find the location on the rule for the top of the next brick course includ- ing a joint, move up the rule until “scale 2” in black is found with a corresponding red number 2, which rep- resents the second course. To find the top of course 3 and consecutive courses, again move up the rule to find the next occurrence of “scale 2“ in black with the red course number. See Figure 3‑14. Course heights for scale 2 A B Brick plus joint height aligns with scale 2 Course number Timothy L. Andera Figure 3‑14. Mason’s rule. A—Mason’s standard brick rule measuring joint and brick that shows the mason’s scale as number 2. B—Mason’s rule measuring a masonry joint and one brick totaling 2 1/2″. A B C D Marshalltown Company Figure 3‑13. Rules with different measuring scales are used depending on the brick or unit size and the layout of the project. A—Standard US customary ruler. B—Oversize brick spacing ruler. C—Standard brick spacing ruler. D—Modular spacing ruler. E—Retractable steel tape. E