What is the minimum specification for weather-resistant sheathing paper used as a wall covering?

The minimum specification for weather-resistant sheathing paper used as a wall covering is accurately defined by requiring at least one layer of #15 asphalt felt that complies with ASTM D 226. This standard ensures that the material provides adequate protection against moisture infiltration, which is crucial for maintaining the structural integrity and longevity of the building's walls.

Asphalt felt is widely used for its durability and effectiveness in resisting weather elements such as water and wind. The #15 grading indicates a heavier weight, which contributes to its resilience against the rigors of weather exposure. Compliance with ASTM D 226 means that the product meets established performance criteria, ensuring it performs effectively in its intended role as a weather barrier.

Utilizing just one layer is often sufficient in many building scenarios, particularly when combined with proper installation techniques and other moisture management strategies. This approach offers both efficiency in material use and effectiveness in performance, aligning with best practices in the construction industry.