CertainTeed M2Tech® 90 Setting Compound is formulated to resist moisture and mold. It is a necessary component for a complete M2Tech moisture and mold resistant system. M2Tech® Shaftliner for use in Shaftwall and Area Separation Firewall Systems is a 1" (25.4mm) thick drywall panel with a specially formulated fire resistive, noncombustible gypsum core, enclosed in a heavy moisture and mold resistant, blue gray colored, 100% recycled paper. M2Tech Shaftliner gypsum panel is designed and engineered for use in constructing lightweight Shaftwall and Area Separation Firewall assemblies. M2Tech Shaftliner gypsum panel is UL/cUL Classified and ULC Listed in fire resistance designs and features double beveled edges for ease of installation. In addition to its fire resistive properties M2Tech Shaftliner gypsum panel is also designed and engineered to provide added protection against mold when exposed to incidental or intermittent moisture during and after construction. When tested for mo...See Moreld resistance by an independent lab at the time of manufacturing, M2Tech Shaftliner achieved the best possible score of 10 per ASTM D3273. See Less