Massachusetts Construction Supervisor License (CSL) Practice Test

Which of the following statements about the placement of masonry units is NOT true?

1. Mortar shall be plastic

2. Surfaces shall be clean and free of deleterious material

3. Units where initial bond is broken shall be removed and relaid

4. Deep furrowing of bed joints is acceptable

The correct answer is: Deep furrowing of bed joints is acceptable

The statement regarding deep furrowing of bed joints being acceptable is not true because proper masonry installation requires each bed joint to be adequately filled with mortar to ensure a strong bond between the units. Deep furrowing can compromise the integrity of the joint by reducing the amount of contact area for the mortar, leading to potential weaknesses in the structure. This practice may also allow for moisture intrusion and can negatively impact aesthetic qualities. In contrast, the other statements reflect correct practices. Mortar being in a plastic state is essential for effective adhesion when placing masonry units, as this allows for adequate bonding and adjustment during installation. Additionally, ensuring that surfaces are clean and free of deleterious material is crucial for achieving a strong bond, as debris can prevent proper adhesion. Lastly, if the initial bond of units is broken, those units must be removed and relaid to maintain structural integrity and alignment, which underscores the importance of careful placement during construction.