A high-quality professional sealant, based on silicone technology. The sealant cures when exposed to moisture/humidity and forms a durable elastic rubber. DOWSIL™ 1000 All Purpose Weathersealant is designed for perimeter sealing of gaps around doors and windows. It has excellent adhesion properties for Unplasticized Polyvinyl Chloride (uPVC) and the alkaline substrates like cement-based plastered substrates. It bonds to form a strong weather-resistant seal.