FortiFlex is a flexible, self-adhering waterproof flashing designed for use with curved window or door openings, sill pans and other penetration flashing applications. It is constructed from a self-adhered rubberized asphalt compound and a cross-laminated polyethylene creped film that features exceptional stretch and durability. The flexible film allows FortiFlex to be stretched around tight arcs, including arched windows and sill pans – while its adhesive compound adheres aggressively to plywood, OSB, aluminum, rigid vinyl, steel and weather-resistive barriers across a wide temperature range.

Its unique construction delivers a dependable seal around nails and other mechanical fasteners – even when fully stretched around a corner. FortiFlex is supplied in convenient 6″ and 9″ widths by 50′ long rolls.