What is the key advantage of using concave joints in masonry?

The key advantage of using concave joints in masonry is their ability to provide enhanced moisture resistance. Concave joints are shaped in such a way that they help direct water away from the joint and prevent it from penetrating into the masonry. This curvature creates a smooth surface that discourages water from accumulating in the joint, which significantly reduces the risk of water intrusion and damage that can result from moisture infiltration. Additionally, the shape of the joint aids in shedding rainwater effectively.

Although other factors like aesthetic appearance, ease of application, and material efficiency may have their own merits in specific contexts, they do not provide the same level of protection against moisture as concave joints do. Thus, their primary advantage lies in improving the longevity and durability of the masonry work through enhanced resistance to water penetration.