Which of the following is true about weather-resistant barriers?

Weather-resistant barriers are critical components in building construction that serve to protect structures from moisture infiltration. The statement that they help prevent moisture from entering the building envelope accurately reflects their primary function. These barriers are designed to be installed behind cladding, such as siding or roofing, to redirect moisture away from the building's vulnerable components, thus reducing the risk of water damage, mold growth, and structural decay.

Their effectiveness lies in the materials used, which are specifically engineered to resist the passage of water while allowing vapor to escape. This vapor permeability is essential as it helps to manage any moisture that may build up inside the walls, where it could lead to deterioration if not properly managed.

The other statements are not accurate in relation to the role and requirements of weather-resistant barriers. Their exclusive installation on roofs would overlook the need for these barriers on walls and other surfaces prone to moisture exposure, while stating that they are not required in construction conflicts with building codes that mandate their use in many climates. Finally, while various materials can be used for weather-resistant barriers, they are not interchangeable; effective barriers must meet specific criteria related to water resistance and air permeability, rather than being made from just any material.