Metacaulk® 835+ is for applications that require a silicone-based firestop. Designed for use with PVC pipe on closed (pressure) systems, EMT, insulated and uninsulated steel pipe, construction and control joints and interior expansion joints. Flexible, non-sag and low odor sealant for exterior or interior use. Used in systems where dynamic movement is expected. Metacaulk 835+ is a one component, fire-rated elastomeric neutral, moisture cure silicone sealant for use in through-penetration firestops and construction joints. In the event of a fire, Metacaulk 835+ will prevent the spread of flames, smoke, gas and water through penetration openings. Metacaulk 835+ caulk grade is a flexible, non-slumping sealant with excellent moisture resistance. For use in interior or exterior expansion and control joints and interior or exterior penetrations. Metacaulk 835+ is protected in a wet stage as well as in a dry stage against mold growth with a combination of biocides.