Buttering a joint is the technique of applying a layer of mortar directly to the end of a brick with a trowel before setting it, so the head joint is fully filled rather than relying only on mortar already on the wall.
A quick swipe of mortar on the wall side of a joint alone often leaves a partial, void-filled head joint once the brick is shoved into place. Buttering the brick's end first, then setting it against the mortar already spread, fills the joint from both sides and produces a solid, void-free connection. It takes more time per brick than skipping the step, which is exactly why it's a detail that separates careful work from rushed work.
Voids in head joints are a common, hidden failure point. They don't show from the face of the wall, but they give water a direct path into the wall assembly, and in a climate that freezes and thaws all winter, that trapped water is what eventually cracks mortar loose or pops a brick face. Fully buttered joints on both sides go a long way toward keeping that from happening in the first place.
More masonry vocabulary from the glossary.
The services where this term comes up.
Chelo's Brick & Stone serves Hillsville, Galax, Wytheville, Fancy Gap, and Independence, VA. Call for a straight answer and a free on-site estimate.
