What systems have replaced Grade D paper and #15 felt in many markets?

The reason why house wraps, liquid coatings, and wall sheathing with an integrated weather-resistive barrier (WRB) have become the preferred systems to replace Grade D paper and #15 felt in many markets lies in their enhanced moisture management and durability properties.

House wraps are designed to allow moisture vapor to escape while preventing water from entering the building envelope. This helps to reduce the risk of mold and structural damage, making them a more effective option than traditional paper products. Liquid coatings offer seamless protection against water ingress, further enhancing the integrity of the walls by eliminating potential points of failure found in traditional felt applications. Integrated WRB sheathing combines structural support with moisture management, streamlining the installation process and improving overall building performance.

These modern materials not only meet but often exceed performance benchmarks compared to traditional options, contributing to energy efficiency and longevity in construction projects. This shift in market preference is driven by both advancements in technology and the increased focus on building science and sustainability in modern construction practices.