ROXUL COMFORTBOARD IS (Insulated Sheathing) is a rigid stone wool product that helps to provide a continual layer of thermal protection to the building envelope. ROXUL products are made of basalt rock and recycled steel slag and are fire resistant, sound absorbent and water repellant. Vapour Permeable, COMFORTBOARD IS provides for greater outward drying when compared to foam plastics such as XPS, Polyiso, or EPS. This drying ability results in a much more durable wall assembly. This video focuses on the installation details for COMFORTBOARD IS around windows.