Which mortar joint profile is typically pressed into a rounded trough to maximize weather resistance?

• A. Beaded joint
• B. Concave joint
• C. Flush joint
• D. Raked joint

Answer: (B)

The way mortar joints shed water controls how well a brick wall resists weather. A concave joint is pressed into a rounded trough, forming a smooth curve that channels water away from the masonry surface and reduces the amount of moisture that can wick into the joint. This rounded channel minimizes capillary action and makes the joint less prone to water intrusion, which is why it’s best for weather resistance.

The other profiles behave differently: a beaded joint creates a raised bead on the surface that can trap water in the bead area; a flush joint is flat and offers little guidance for water runoff; a raked joint is recessed and can hold moisture in the gap, increasing vulnerability to weathering.