3-21. Using a String Line. To lay stretcher courses between the leads, you will need to use a string
a. Constructing the Line. Drive the nails into the mortar joint to support the line. Attach the line to
the nail in the left-hand lead, pulling it tight. After the line is firm, attach the line to the nail in the right-
hand lead (Figure 3-25).
Figure 3-25. Using the string line
b. Laying the First Course. Having the string line in place, lay the first stretcher course between the
two corner leads. Push the bricks into position so that their top edges are 1/16 inch behind the line.
c. Laying the Remaining Courses. For the next course, move the string line up to the next mortar
joint. Lay the course as before, finishing the face joints before the mortar hardens. The wall should be
checked at several points, making sure it is level and plumb.