Firestop Sealant MC 350i


/ Through Penetrations firestop wall / floor

Metacaulk® 350i Intumescent Firestop Sealant

Firestop Product Information:

Metacaulk® 350i is a one-component, general purpose fire-rated sealant and smoke seal for construction joints and through-penetrations. Metacaulk® 350i is an intumescent, water-based, non-sag caulking grade sealant that is easy to apply and great for retrofits. It cures to an elastromeric seal that is suitable where dynamic movement is expected. Sound Transmission Class (STC) rating 53, Tested in a UL 411 wall assembly/section to ASTM E90


Firestop Additional Information:

Metacaulk® 350i is a one component, general purpose fire rated sealant and smoke seal for construction joints and through-penetrations. Metacaulk® 350i is a water based, extremely intumescent, non-sag caulking grade sealant that is easy to apply as well as to retrofit. It cures to an elastomeric seal that is suitable where dynamic movement is expected. In the event of a fire, Metacaulk® 350i will prevent the spread of flames, smoke, hot gases and water through joint openings and throughpenetrations. No dilution or mixing is required for use. No special skills are necessary for installation. Metacaulk® 350i is applied with a conventional caulking gun, bulk loading gun or can be troweled from the pail. For large applications, it can be pumped directly from the pail. Metacaulk® 350i systems are rated for 1, 2 and 3 hours in accordance with the ASTM E814 (UL1479),UL 2079 and ULC-S115-95 test standards. Metacaulk® 350i is protected in a wet stage as well as in a dry stage against mold growth with a combination of biocides.

Firestop Product Document Downloads:


Firestop Key Features:

• Highly Intumescent
• Water Based
• Excellent Freeze-Thaw
• Flexible Set
• Paintable
• VOC Compliant
• Safe and Easy to Use
• Minimum 3 Year Shelf Life
• Protected against mold growth

Firestop Typical Applications:

Top of the Wall Construction Joints
Deflection Track Wall Systems
Up to 2" (51 mm)PVC/CPVC (Open)
Crosslinked Polyethylene (PEX) 
Steel, Copper, Cast Iron and
EMT Pipe
Flexible Conduit
Fiberglass Insulated Pipe
Armaflex Insulated Pipe
Telephone, Communication and Power 
HVAC Ductwork