Red Seal Bricklayer Practice Exam

What type of mortar joint thickness is generally considered acceptable?

1. 1/8 inch

2. 1/2 inch

3. 3/8 inch

4. 7/8 inch

The correct answer is: 3/8 inch

A mortar joint thickness of 3/8 inch is typically considered acceptable in bricklaying because it strikes a balance between providing sufficient support and stability for the masonry units while allowing for the slight variations in brick size and the natural imperfections that can occur during construction. This thickness also helps to achieve a visually appealing appearance, ensuring uniformity across the completed work. Mortar joints that are too thin, like 1/8 inch, may not provide enough bonding area for the bricks and could lead to structural weaknesses. On the other hand, a mortar joint that is too thick, such as 1/2 inch or 7/8 inch, can compromise the aesthetic quality of the masonry and could result in increased susceptibility to cracking and other structural issues as the mortar expands and contracts. Therefore, a 3/8 inch joint is widely recommended as it offers a good compromise in terms of strength, aesthetics, and construction efficiency.