The policy that no joints should be in direct alignment across any _______ adjacent courses applies to how many adjacent courses?

The policy that no joints should be in direct alignment across any _______ adjacent courses applies to how many adjacent courses?

• A. two
• B. three
• C. four
• D. five

Answer: (B)

The idea is to prevent a straight, continuous seam down the roof by staggering the joints. The rule specifically requires that across any three adjacent courses, the joints must not line up in the same place. By ensuring there isn’t a single joint running through three consecutive rows, you create a stepped pattern that blocks water from following a long, direct seam and improves weather resistance. This balance keeps installation practical while reducing the risk of leaks and wind-driven damage. Shorter alignments across two consecutive courses aren’t ruled out by this rule, but extending the alignment beyond three courses would weaken the seam too much.

The idea is to prevent a straight, continuous seam down the roof by staggering the joints. The rule specifically requires that across any three adjacent courses, the joints must not line up in the same place. By ensuring there isn’t a single joint running through three consecutive rows, you create a stepped pattern that blocks water from following a long, direct seam and improves weather resistance. This balance keeps installation practical while reducing the risk of leaks and wind-driven damage. Shorter alignments across two consecutive courses aren’t ruled out by this rule, but extending the alignment beyond three courses would weaken the seam too much.