What is the primary purpose of house wrap?

The primary purpose of house wrap is to block water while allowing vapor to escape. This is crucial in a building's envelope because it helps prevent moisture from penetrating the walls, which can lead to mold growth, wood rot, and other structural issues. The house wrap serves as a barrier against rain and snow, protecting the insulation and framing materials inside the walls. At the same time, it is designed with permeability features that let moisture vapor generated from inside the building escape, helping to maintain a balanced moisture level within the wall assembly. This efficacious management of water and vapor is vital for the longevity and durability of the building structure.