Flex Seal Flex Paste Super Thick Waterproof Rubberized Paste 1 lb. Black

Bring durable, long-lasting protection to your toughest sealing and coating jobs with Flex Paste Super Thick Waterproof Rubberized Paste. This high-viscosity sealant clings to vertical, overhead, and submerged surfaces, instantly filling cracks, gaps, and holes to form a strong, flexible rubber membrane. Whether you’re repairing leaks, patching roofing, or creating custom gaskets, Flex Paste delivers professional-grade performance for indoor and outdoor projects.

Formulated for ultimate versatility, this black rubberized paste bonds to wood, metal, concrete, tile, fiberglass, PVC, brick, stucco, fabric, and more—even when surfaces are wet or underwater. Once cured, it remains flexible under temperature extremes, resists UV, chemicals, and mildew, and can be painted to match any finish. From DIY fixes to contractor-level applications, Flex Paste is the go-to solution for sealing, coating, and protecting virtually any surface.

Key Features

• Super-thick, non-slumping paste consistency for overhead and vertical applications
• Waterproof rubber seal that fills and bridges gaps, cracks, and holes
• Bonds to wet or dry surfaces—even underwater
• Cures to a flexible, tear-resistant rubber membrane
• Paintable to blend with any surface color
• UV-, chemical-, and mildew-resistant for long-term durability
• Withstands temperatures from –40 °F to 200 °F
• Ideal for roofing repairs, plumbing leaks, foundation cracks, outdoor gear, crafts, and more

⚠️ WARNING: This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.