Construction Supervisor License Practice Exam 2025 – All-in-One Study Guide for Exam Success!

The minimum water-resistant barrier that must be attached to the sheathing on an exterior wall is indeed one layer of 15-pound asphalt felt. This option is widely recognized within building codes and construction practices for its ability to provide an effective moisture barrier.

The 15-pound asphalt felt serves as a secondary defense against water intrusion, protecting the sheathing and framing from moisture that may penetrate the exterior cladding. Its characteristics include being lightweight and manageable, yet it provides adequate resistance to the passage of water and helps protect against wind-driven rain.

Other materials listed, such as 30-pound asphalt felt or Tyvek Home Wrap, certainly offer enhanced moisture protection, but the standard for minimum compliance often references 15-pound asphalt felt due to its long-standing use and code requirements in various regions. Six mil polyvinyl chloride, while also effective, is not typically categorized as the minimum barrier in standard practice, making the 15-pound asphalt felt the correct response in this scenario.