RectorSeal Metacaulk® MC 835+ Self-Leveling Firestop Sealant – Gray, 10.15 oz Cartridge

Protect horizontal fire-rated penetrations with confidence using RectorSeal Metacaulk® MC 835+ Self-Leveling Firestop Sealant. Engineered with advanced neutral-cure silicone technology, this premium firestop sealant creates a flexible, durable barrier that helps prevent the spread of fire, smoke, toxic gases, and moisture through floor penetrations and construction joints. Designed for applications where dynamic movement is expected, it delivers long-lasting performance in both interior and exterior environments.

Its self-leveling formula flows smoothly into horizontal openings, creating a consistent seal without the need for tooling. The one-component, ready-to-use silicone requires no mixing, offers excellent weather and chemical resistance, and cures to a flexible elastomeric seal that remains reliable even under continuous movement. Compatible with CPVC systems and protected against mold growth, Metacaulk® MC 835+ is an ideal choice for demanding commercial and industrial projects.

Whether you're sealing pipe penetrations, cable openings, floor joints, or curtain wall systems, Metacaulk® MC 835+ Self-Leveling provides dependable firestop performance while simplifying installation and helping contractors meet today's building code requirements.

Key Benefits

• One-component, self-leveling silicone firestop sealant
• Designed for horizontal floor penetrations and joint applications
• Helps prevent the spread of fire, smoke, toxic gases, and moisture
• Flexible elastomeric seal ideal for dynamic movement
• Excellent weather, UV, and chemical resistance
• Low-odor, neutral-cure silicone formulation
• No mixing required—ready to use
• Mold-resistant protection in both wet and dry conditions
• STC Rating 55 for improved acoustic performance
• Suitable for both interior and exterior applications

Recommended Applications

• Horizontal floor penetrations
• Curtain wall joints
• Construction and control joints
• Expansion joints
• EMT conduit penetrations
• Steel pipe penetrations
• Electrical and telecommunications cable penetrations
• Commercial, industrial, and institutional construction