Housewrap is a special type of vapor barrier for buildings that ___.

Housewrap is specifically designed to act as a barrier against water while permitting water vapor and gases to escape from inside the building to the outside environment. This property is critical in maintaining a healthy indoor air quality and preventing moisture build-up within wall assemblies, which can lead to mold and structural damage.

The function of housewrap is to keep rain and bulk water from penetrating the walls, while still allowing the wall assembly to breathe. This balance between being water-resistant and vapor-permeable is what distinguishes housewrap from other materials that may seal off gas and moisture exchange entirely, which could create hazardous conditions in the building envelope.

Notably, housewrap is installed during the construction phase, not after finishing work has been completed. Sealing at joints can also be necessary to ensure maximum effectiveness of the barrier, particularly in areas subject to more extreme weather conditions. Thus, the properties of housewrap align with its intended use, emphasizing its role in effective moisture management in building construction.