What is significantly more effective than a vapor diffusion retarder?

Air sealing is significantly more effective than a vapor diffusion retarder because it directly controls the movement of air into and out of a building. While vapor diffusion retarders help to limit moisture transfer through building materials due to vapor diffusion, they do not address the air leaks that can allow moist air to enter and exit the building.

Air sealing minimizes unwanted airflow that can introduce humidity, dampness, and cold air into a home. By filling gaps, cracks, and openings in the building envelope, air sealing helps maintain indoor air quality and enhances energy efficiency. This reduces the risk of condensation problems that can occur when warm, humid air meets cooler surfaces indoors.

In summary, air sealing is crucial for keeping moisture levels in check, preventing potential structural issues, and enhancing overall comfort within a home, making it a more effective strategy than relying solely on a vapor diffusion retarder.