What is the minimum thickness required for wood structural panel sheathing under asphalt shingles that are exposed on the underside of a covered patio?

The minimum thickness requirement for wood structural panel sheathing under asphalt shingles is 3/8 inch. This thickness provides adequate strength and performance while supporting the weight of the shingles and handling environmental factors such as moisture and temperature changes.

Wood structural panels typically need to meet specific guidelines to ensure they can bear loads effectively and maintain structural integrity, especially when exposed to potential moisture or other conditions related to being under a covered patio. A thickness of 3/8 inch strikes a balance between structural support and weight considerations for asphalt shingles.

Thinner options, such as 1/4 inch, often fail to meet the necessary strength standards and may lead to issues such as warping or splitting over time. The thicker alternatives, like 1/2 inch and 5/8 inch, exceed the minimum requirement and, while they may offer greater durability, are not necessary for the specified application under a covered patio where 3/8 inch is adequate.