Waterproof foam;BK;E2

Waterproof foam BK E2 is a black, one-component polyurethane foam designed to seal, insulate, and protect against moisture intrusion. Its dark color helps it blend with concrete, masonry, and dark trims, delivering a discreet, durable seal for a wide range of indoor and outdoor projects.

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  Expands to fill gaps and voids with controlled expansion, creating a seamless, air-tight seal in irregular spaces.


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  Water-resistant cured seal that stands up to weather, humidity, and routine movement, helping prevent drafts and moisture intrusion.


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  Flexible and durable after curing, maintaining integrity through temperature changes and building settlement.


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  Adheres to common substrates including concrete, brick, wood, metal, and certain plastics for versatile use around the home or job site.


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  Can be trimmed flush after curing for a clean finish that won’t interfere with trim or paint work (where compatible).


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  Interior and exterior capable to tackle sealing, insulation, and damp-proofing across a variety of environments.


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  One-component, ready-to-use formula with no mixing required—apply quickly with a standard foam can and nozzle.

Where it shines

Use Waterproof foam BK E2 to seal around windows and doors, seal pipe penetrations, attic or crawl-space joints, and outdoor seams where moisture resistance and insulation are needed. It’s especially effective for gaps that are too large for traditional caulks and too irregular for rigid sealants, providing a robust barrier against air leaks and moisture.

How it works

Once applied, the foam reacts with ambient moisture and expands to fill cracks and voids. It cures into a flexible, water-resistant seal that remains workable for trimming and finishing. The black color helps minimize visible seams on darker surfaces, reducing the need for heavy concealment or repainting.

Application tips for best results

Shake well before use and attach the nozzle securely. Apply in short bursts from corners to center of gaps, allowing the foam to expand gradually. For vertical surfaces, apply in layers to prevent sagging, and trim flush after curing for a neat finish. Wear protective gloves and work in a well-ventilated area; avoid contact with skin and eyes. Store upright in a cool, dry place away from heat sources.

Who benefits most

• Homeowners tackling weatherproofing, draft reduction, and damp-proofing projects


• Renovators and DIY enthusiasts seeking a simple, effective gap-filling solution


• Contractors and property managers needing reliable exterior sealant for multiple substrates

Why choose Waterproof foam BK E2

Unlike generic sealants, BK E2 combines ease of use with robust, moisture-resistant performance and a discreet black finish that helps blends with darker building materials. It fills irregular gaps more effectively than thin caulks, providing both insulation value and a durable moisture barrier. With its one-component formula, it’s a practical, time-saving option for rapid repairs and long-lasting protective seals.

Safety and disposal

Use protective gloves and eye protection during application. Allow the foam to cure fully before trimming. Dispose of empty cans according to local regulations and keep contents away from heat sources.