To increase energy efficiency, buildings are being built with extreme airtightness. In the past, drafts coming through exterior walls would keep the wall cavity dry. But relying on drafts isnt a good plan, hence the high performing air and moisture barriers of today. Tighter buildings are designed to prevent outside air and bulk water from entering, and allow moisture vapor to escape. Building wraps are easily damaged. The solution? High-performance membranes to increase airtightness.