Firestopping COMPREHENSIVE SOLUTIONS. PROFESSIONAL ENGINEERING SUPPORT. ON-SITE ASSISTANCE. Tremco's firestopping products are designed and engineered as integral components to critical high-performance UL rated systems. EFFECTIVE. DURABLE. HIGH-PERFORMANCE. Our TREMstop® line of fire protection products feature sealants, intumescents, devices and forming material to properly seal these joints and penetrations, helping to ensure the performance of the fire-rated system. Our library also includes more than 400 independently tested, fire-rated systems for through penetrations and joints.