Composition: High quality, long fibered, specially treated water- and weather-resistant plies. Plies are pressure laminated with a special water-resistant adhesive. Less labor:Install the sheathing and air- and weather-resistant barrier in one step. High performing: Weather resistant barrier on both sides for higher performance. Easier to handle: Lighter-weight:Thermo-Brace is easier for one person to install with less risk of a back injury. Ease of installation: Nail patterns are printed on the face for ease of installation.