Polylok Butyl Sealant is a flexible, non-shrinking joint sealant made for precast concrete applications. It forms a strong, permanent bond to concrete, metal, and plastic, and resists water, chemicals, and temperature extremes. It won’t harden, oxidize, or crack over time, making it ideal for underground structures, septic tanks, and other demanding conditions. Easy to apply and ASTM compliant, it provides long-lasting joint protection in tough environments.