Brickwork Terminology – Meaning of “Frog” in a Standard Modular Brick In building construction practice, the term “frog” refers to which feature provided on a brick to improve bedding and bond with mortar?

Introduction:
The term “frog” is fundamental brickwork terminology encountered in site drawings, specifications, and viva questions. Understanding what the frog actually is helps masons and engineers place bricks correctly to achieve better bond, bedding, and durability of masonry courses.

Given Data / Assumptions:

• A standard burnt clay brick typically has a shallow, rectangular depression on one of its larger faces.
• This depression is intentionally created during moulding.
• The purpose is to receive mortar and improve mechanical keying.

Concept / Approach:

A frog increases the effective contact and interlocking of mortar with the brick. When properly oriented during laying, it reduces slippage, improves bond strength, and ensures adequate mortar thickness across the bed joint, thereby enhancing the structural performance and finish quality of the wall.

Step-by-Step Solution:

Verification / Alternative check:

Practical masonry handbooks define frog as a depression on the bed face that enhances bond and mortar grip. Site standards also instruct how to orient frogs in different courses to achieve even bedding.

Why Other Options Are Wrong:

Apparatus for lifting stones is unrelated to brick anatomy. A vertical joint is a gap filled with mortar between bricks. Soaking is a preparatory process, not a brick feature. Chamfers are edge treatments and not termed as frogs.

Common Pitfalls:

Confusing the frog with random chips/defects; assuming it is merely decorative rather than functional for bedding and bond.

Final Answer:

A rectangular depression on one large face of a brick to hold mortar