Types of pointing — identify the description Which pointing type is described as having the upper side of mortar joints kept about 12 mm inside the masonry face while the bottom edge is kept flush with the wall surface?

Introduction / Context:
Pointing finishes the exposed edges of mortar joints in masonry to improve appearance and weather resistance. Different profiles (flush, recessed, struck, grooved, weathered) offer varying degrees of water-shedding capability and visual character. Correct identification is important for specifications and site execution.

Given Data / Assumptions:

• Description: upper side (top arris) set back ~12 mm, bottom kept flush with the face.
• We compare standard pointing types.
• Terminology occasionally appears with typographical errors (e.g., “truck” vs “struck”).

Concept / Approach:
Struck pointing has a sloping profile: the top edge is recessed while the bottom edge is flush, creating a downward slant that sheds water effectively. Recessed pointing sets back the entire joint depth uniformly. Grooved provides a central groove; flush is finished level with the masonry face. Hence, the described profile corresponds to struck pointing, not recessed or flush.

Step-by-Step Solution:

Verification / Alternative check:
Site practice and textbooks depict struck/weathered pointing for superior rain-shedding since water runs off the sloping surface rather than ponding in the joint.

Why Other Options Are Wrong:

• recessed pointing: whole joint set back; not just the top edge.
• grooved: includes a central groove; does not match the description.
• flush: even with face; no recess on top.
• truck pointing: non-standard spelling; intended term is “struck.”

Common Pitfalls:
Confusing struck with recessed; forgetting that sloped profiles improve water run-off on exterior walls.

Final Answer:
struck pointing