What is the primary use of a buttering trowel in masonry?

The primary use of a buttering trowel in masonry is to spread mortar on a unit. This specialized trowel is designed with a broad, flat blade, which allows for efficient application of mortar onto the surfaces of masonry units, such as bricks or blocks, before they are placed in position. The act of buttering applies a layer of mortar that helps in achieving a strong bond between the units when they are laid. This is particularly important in ensuring proper adhesion and helping to create a tight, controlled joint between bricks, which affects both the structural integrity and aesthetic appearance of the wall.

Using a buttering trowel correctly allows the mason to control the thickness of the mortar layer and ensures that there are no gaps or voids that could compromise the strength of the wall. This tool is specifically designed for this task and differs from other masonry tools, which serve different purposes, such as checking for level, splitting units, or tooling joints.