Brickwork terminology: The alignment of a cross joint exactly along the plumb line is called a…

Introduction / Context:
Correct masonry terminology is essential for setting out, supervision, and measurement. Vertical alignment of cross joints affects both appearance and structural behavior in bonded brickwork. The term for a perfectly plumb vertical joint is routinely used on drawings and at site.

Given Data / Assumptions:

• We are discussing brick masonry with alternating headers and stretchers.
• “Cross joint” refers to the vertical joint between bricks in adjacent units/courses.
• Plumb alignment is a desired quality criterion.

Concept / Approach:
“Perpend” denotes a vertical joint kept truly plumb. Good bonding practice staggers perpend alignment between consecutive courses to avoid continuous vertical lines that weaken the wall; however, within a course or specified pattern, individual perpends must be plumb. “Bed block” and “lintel” describe different elements, while “vertical line” and “string line” are generic words, not the masonry term of art.

Step-by-Step Solution:
Define the feature: a vertical mortar joint.Assign the masonry term: “perpend.”Differentiate from non-technical labels and unrelated components.Select “Perpend.”

Verification / Alternative check:
Masonry handbooks and site checklists specify “plumb perpend joints” as an acceptance criterion.

Why Other Options Are Wrong:
Bed block: Bearing block/stone, not a joint alignment.Lintel: Horizontal load-bearing member over openings.Vertical line/String line: Generic descriptors, not the formal term.

Common Pitfalls:
Letting perpends drift out of plumb, causing visual misalignment and potentially weak planes through the wall.

Final Answer:
Perpend.