• Highly Intumescent Fire Protection: Expands under high heat exposure to help block the spread of flames, smoke, and hot gases through fire-rated assemblies.
• Flexible Elastomeric Performance: Cures to a flexible seal capable of handling vibration, movement, and dynamic joint expansion in wall and floor systems.
• Large Scale Application Ready: 5 gallon pail packaging is ideal for commercial construction projects and can be pumped directly from the pail for faster installation.
• Water-Based Formula: Low odor, water-based formulation requires no mixing or dilution and allows for easier cleanup.
• Smoke & Acoustical Seal: Functions as both a firestop sealant and acoustical smoke sealant for rated assemblies and penetrations.
• Multiple Application Methods: Can be applied by trowel, bulk loading gun, conventional caulking gun, or pumping equipment.
• Mold Resistant Protection: Protected against mold growth in both wet and cured stages with incorporated biocides.
• Excellent Freeze-Thaw Stability: Designed to maintain performance through freeze-thaw cycles during storage and transport.
• Paintable Finish: Can be painted after curing for a clean, professional finished appearance.
• UL & ASTM Tested: Tested to UL 2079, UL 1479, ASTM E1966, ASTM E119, ASTM E90, and CAN/ULC firestop standards.

Tested Standards

• ASTM E1966 / UL 2079
• ASTM E119 / UL 263
• UL 1479
• ASTM E90
• CAN/ULC S115, S101, S102

• Fire-rated construction joints
• Through-penetration firestop systems
• Gypsum wallboard assemblies
• Concrete wall and floor penetrations
• Corrugated steel deck assemblies
• EMT conduit penetrations
• Cable and wire penetrations
• Insulated pipe penetrations
• Dynamic movement joints
• Smoke sealing applications
• Acoustical sealing applications
• Commercial and industrial construction projects

Metacaulk 350i is designed for interior firestop applications on both vertical and horizontal surfaces. The sealant can be applied using standard caulking techniques, troweled directly from the pail, or pumped for large-scale installations.

No mixing or dilution is required before use. Apply only within recommended temperature ranges of 40°F to 120°F. When backing or damming materials are required, use only materials approved for the specific UL firestop assembly.

Best Practices

• Store between 35°F and 120°F
• Protect from freezing whenever possible
• If frozen, thaw completely before use
• Keep containers sealed when not in use
• Follow UL system listings for proper installation depth and joint design

Metacaulk 350i is not intended for continuous water immersion or constantly wet environments and should not be applied against uninsulated surfaces exceeding 300°F.