Red Seal Bricklayer Practice Exam

The correct answer is sand, as it serves as the primary aggregate in mortar mixes. Mortar is typically composed of a binder, such as cement or lime, and aggregates, where sand plays a crucial role in providing strength, stability, and workability. The fine particles of sand help in filling the voids between the cement or lime particles, improving the overall consistency and performance of the mortar when applied between bricks or masonry units.

In contrast, wood, metal, and plastic are not suitable materials for mortar. Wood can deteriorate when exposed to moisture and does not provide the necessary binding properties. Metal is too rigid and does not bond effectively with the other components in a mortar mix. Similarly, plastic lacks the structural integrity required in mortar applications and does not contribute to the desired physical properties associated with traditional masonry processes. Therefore, sand's unique characteristics make it an essential component of mortar.