According to Walker's, what factor determines the end lap length for metal siding laid on roofs?

According to Walker's, what factor determines the end lap length for metal siding laid on roofs?

• A. Roof pitch
• B. Material thickness
• C. Wind load
• D. Roof height

Answer: (A)

End lap length for metal siding laid on roofs is controlled by how water drains off the roof, which is set by the roof pitch. The pitch determines how long water sits at the seam and how quickly it moves away. On a shallow (low-pitch) roof, water lingers more at the end lap, so a longer lap helps prevent leaks. On a steep roof, water runs off faster, allowing a shorter end lap without compromising sealing. This relationship keeps the seam watertight under the expected drainage conditions. Other factors like wind effects or overall height influence different installation aspects, but the lap length itself is guided by roof pitch.

End lap length for metal siding laid on roofs is controlled by how water drains off the roof, which is set by the roof pitch. The pitch determines how long water sits at the seam and how quickly it moves away. On a shallow (low-pitch) roof, water lingers more at the end lap, so a longer lap helps prevent leaks. On a steep roof, water runs off faster, allowing a shorter end lap without compromising sealing. This relationship keeps the seam watertight under the expected drainage conditions. Other factors like wind effects or overall height influence different installation aspects, but the lap length itself is guided by roof pitch.