Final answer:
Weather-resistive barriers like Tyvek are primarily designed to protect against moisture, contributing to the energy efficiency of a building by keeping insulation materials dry.
Step-by-step explanation:
Weather-resistive barriers (WRBs) like Tyvek are designed to protect against moisture. These materials are used in building construction to prevent water from getting into the walls, which can cause damage such as mold, mildew, and structural deterioration.
While Tyvek does contribute to the overall energy efficiency of a building by helping to maintain a dry insulation environment, its primary function is not to provide insulation or structural support. However, by keeping the insulation dry, Tyvek indirectly helps insulation materials perform more efficiently, because wet insulation has a lower R-value and is less effective at preventing heat transfer.