Brick is laid on concrete foundations. The first bed of mortar joint shall be what maximum thickness?

• A. 1-1/2 Inch
• B. 3/4 Inch
• C. 1 Inch
• D. 2 Inches

Answer: (B)

The point being tested is how thick the initial mortar bed under the first course of brick on a concrete foundation should be. On a concrete footing, the first bed needs enough mortar to fill small irregularities and give a level starting point, but not so much that it creates an overly thick, weak bond or causes misalignment for the rest of the wall. The standard maximum for that first bed is three-quarters of an inch. This thickness allows the bricks to sit evenly and establish a solid base for subsequent courses, while keeping the bond area and overall stability intact. Larger bed thicknesses—such as 1 inch, 1-1/2 inches, or 2 inches—would introduce excessive mortar, jeopardize bonding with the foundation, and increase the risk of movement or cracking as the wall bears loads.