Which statement is true regarding joints across three adjacent courses?

Which statement is true regarding joints across three adjacent courses?

• A. Joints must align at every third course
• B. Joints must not align across any three adjacent courses
• C. Joints alignment is unrestricted
• D. Joints align on every second course

Answer: (B)

The pattern here aims to keep seams from forming a continuous line through three consecutive layers, which helps prevent water from finding an unbroken path down the roof. If a joint appears in the same location across three adjacent courses, water can travel straight through that vertical line. By ensuring that, across any three successive courses, a joint isn’t aligned in the same spot, you create a staggered layout that blocks that potential leak path. That’s why the statement that joints must not align across any three adjacent courses is the true one. If joints were allowed to follow a fixed alignment pattern or were unrestricted, there would be windows where three consecutive courses line up, reintroducing a continuous seam and increasing the risk of leakage.

The pattern here aims to keep seams from forming a continuous line through three consecutive layers, which helps prevent water from finding an unbroken path down the roof. If a joint appears in the same location across three adjacent courses, water can travel straight through that vertical line. By ensuring that, across any three successive courses, a joint isn’t aligned in the same spot, you create a staggered layout that blocks that potential leak path. That’s why the statement that joints must not align across any three adjacent courses is the true one.

If joints were allowed to follow a fixed alignment pattern or were unrestricted, there would be windows where three consecutive courses line up, reintroducing a continuous seam and increasing the risk of leakage.