What is the required thickness range for masonry unit bed joints for the second course?

What is the required thickness range for masonry unit bed joints for the second course?

• A. 1/8 inch to 1/4 inch
• B. 1/4 inch to 1/2 inch
• C. 1/2 inch to 3/4 inch
• D. 3/8 inch to 5/8 inch

Answer: (B)

Bed joints are the horizontal layers of mortar that bond each course of masonry units. For the second course, the recommended thickness is 1/4 inch to 1/2 inch. This range provides enough mortar to develop a good bond and accommodate minor variations in unit size, while avoiding a joint that’s too thick, which can weaken the bond, cause sagging or misalignment, and make it harder to keep the wall plumb. If the joint is too thin, the units may not bed properly and the bond may be poor; if it’s too thick, it can reduce strength and lead to uneven surfaces. Sticking to this range helps ensure a solid, stable second course and sets a consistent foundation for the courses that follow.

Bed joints are the horizontal layers of mortar that bond each course of masonry units. For the second course, the recommended thickness is 1/4 inch to 1/2 inch. This range provides enough mortar to develop a good bond and accommodate minor variations in unit size, while avoiding a joint that’s too thick, which can weaken the bond, cause sagging or misalignment, and make it harder to keep the wall plumb. If the joint is too thin, the units may not bed properly and the bond may be poor; if it’s too thick, it can reduce strength and lead to uneven surfaces. Sticking to this range helps ensure a solid, stable second course and sets a consistent foundation for the courses that follow.