Waterproof Gap Sealant Mastic | Flexible, Fast-Curing 2-Pack

Seal openings around pipes, conduits, and wall penetrations with a mastic designed to form an airtight, watertight barrier. Its dense formula expands slightly as it is applied to help fill small gaps and block moisture, air leaks, and pest entry.

Useful for indoor and outdoor repairs

• Adheres to wood, concrete, metal, PVC, and drywall without a primer.
• Forms a flexible seal that resists peeling and cracking as temperatures change.
• Fast-curing formula helps reduce repair downtime.
• Low-odor formula is described as containing no VOCs or toxic additives; the formulation is also non-flammable and non-corrosive.
• Suitable for new construction and retrofit work in areas such as basements, bathrooms, and outdoor installations.

Product details

• Materials: polydimethylsiloxane, polyurethane, silica, methyl methacrylate, and epoxy resin.
• Apply above 5°C (41°F) for optimal curing.
• Listed dimensions: 10.6 × 6 cm (4.17 × 2.36 in).
• Package includes two waterproof sealant mastic units.

Before and after application

For best adhesion, apply to surfaces that are clean, dry, and free of dust or grease. Keep water away while the mastic begins to cure. Wear gloves during application and wash hands thoroughly after handling uncured material. Store sealed in the original packaging in a cool, dry place.