Which material is commonly used as a vapour barrier in construction?

Polyethylene is commonly used as a vapor barrier in construction because of its effectiveness in preventing moisture from passing through walls, ceilings, and floors. As a synthetic plastic, polyethylene is non-porous, which means it does not allow water vapor to diffuse through it easily. This characteristic helps control humidity levels within buildings, thereby protecting structural integrity and minimizing issues related to mold and mildew development.

In various building codes and construction practices, the use of polyethylene sheeting in areas such as basements, crawl spaces, and exterior walls is often required to safeguard against moisture intrusion. Proper installation ensures that the vapor barrier is sealed adequately, providing a strong defense against water vapor that could compromise insulation and lead to potential damage over time. This makes polyethylene the preferred choice for effective vapor control in both residential and commercial construction.