Single wall chimney or vent connectors shall be fastened with a minimum of _______ equally spaced screws.

Single wall chimney or vent connectors shall be fastened with a minimum of _______ equally spaced screws.

• A. 4
• B. 3
• C. 2
• D. 5

Answer: (B)

Securely fastening a single-wall vent connection relies on enough fasteners to resist movement and keep the joint sealed during temperature changes and draft. Using a minimum of three screws placed evenly around the circumference provides balanced clamping force, preventing the joint from loosening as the vent heats and cools. Two screws can allow rotation or loosening, while more screws aren’t required by this rule, but adding them isn’t the point here—the emphasis is on even distribution to maintain a reliable seal.

Securely fastening a single-wall vent connection relies on enough fasteners to resist movement and keep the joint sealed during temperature changes and draft. Using a minimum of three screws placed evenly around the circumference provides balanced clamping force, preventing the joint from loosening as the vent heats and cools. Two screws can allow rotation or loosening, while more screws aren’t required by this rule, but adding them isn’t the point here—the emphasis is on even distribution to maintain a reliable seal.