What is the minimum sidelap required between adjacent wood shingle courses?

What is the minimum sidelap required between adjacent wood shingle courses?

• A. 1-1/2 inches
• B. 1 inch
• C. 3/4 inch
• D. 2 inches

Answer: (A)

In wood shingle installation, sidelap is how much of the upper course covers the lower course to shed water and hide joints. The minimum required is 1-1/2 inches, because this amount ensures the seam between courses is sufficiently overlapped to prevent water from penetrating and to keep fasteners of the lower course protected from the next row. Smaller overlaps (like 1 inch or 3/4 inch) can leave gaps that wind-driven rain or movement could exploit, increasing the risk of leaks. A 2-inch overlap is usually more than necessary and can disrupt the typical pattern and material efficiency. So, 1-1/2 inches is the standard minimum for reliable weatherproofing and proper appearance.

In wood shingle installation, sidelap is how much of the upper course covers the lower course to shed water and hide joints. The minimum required is 1-1/2 inches, because this amount ensures the seam between courses is sufficiently overlapped to prevent water from penetrating and to keep fasteners of the lower course protected from the next row. Smaller overlaps (like 1 inch or 3/4 inch) can leave gaps that wind-driven rain or movement could exploit, increasing the risk of leaks. A 2-inch overlap is usually more than necessary and can disrupt the typical pattern and material efficiency. So, 1-1/2 inches is the standard minimum for reliable weatherproofing and proper appearance.