Hercules Plumbing Chemicals 25403 Roof and Flashing Sealant 10.3 Oz Cartridge

Product Description

The Hercules Plumbing Chemicals 25403 Roof and Flashing Sealant is a specially formulated, long-lasting sealant designed for demanding plumbing and roofing applications. This is not a roof coating or roof cement. It is a purpose-built sealant that forms a durable, flexible, and weatherproof coating around both new and existing flashings. Plumbers, roofing contractors, and maintenance professionals rely on this type of product to stop leaks and protect vulnerable transition points on a roof. Common application areas include flashings, cooling towers, skylights, downspouts, gutters, vents, chimneys, and general roof repair zones. The 25403 bonds firmly to a wide range of surfaces, including concrete, metal, tile, roofing materials, and masonry. This broad substrate compatibility makes it a versatile choice for mixed-material repairs where surfaces meet at different angles or joints. One of the standout features of this sealant is its ability to withstand the stress caused by dissimilar rates of thermal expansion. When metal and masonry or concrete and tile are joined, they expand and contract at different rates with temperature changes. A rigid sealant would crack and fail under these conditions. The flexible formulation of the 25403 moves with the structure and maintains a watertight seal over time. The product comes ready to use straight from the cartridge. There is no separation of materials, no stirring required, and no strong or objectionable odor during application. It can be applied to cold or wet surfaces, which is a practical advantage for field work in variable weather conditions. The 25403 meets ASTM D-4586 Type 1 and ASTM D-3409 standards, confirming it has been tested for performance and reliability in roofing sealant applications.

• Forms a flexible, weatherproof seal around flashings, vents, chimneys, gutters, skylights, and cooling towers
• Adheres to concrete, metal, tile, roofing materials, and masonry surfaces
• Ready to apply on cold or wet surfaces with no stirring required and no objectionable odor

Product Highlights

The Hercules Plumbing Chemicals 25403 delivers a durable, flexible, weatherproof seal for roofing and flashing repairs across a wide range of substrates. It meets ASTM D-4586 Type 1 and ASTM D-3409 standards and is ready to use straight from the 10.3 oz cartridge.

Product Information

Standard Information

• Brand: HERCULES PLUMBING CHEMICALS
• Manufacturer Part Number: 25403

Technical Specifications

• Container Type: Cartridge
• Net Content: 10.3 oz
• Applicable Standards: ASTM D-4586 Type 1, ASTM D-3409
• Surface Compatibility: Concrete, Metal, Tile, Roofing, Masonry
• Application Conditions: Can be applied on cold or wet surfaces