DAP® high-heat mortar is a non-combustible silicate cement used for patching chipped firebrick in fireplaces and sealing wood burning stoves. High-heat mortar adheres firmly to the firebrick when wet or dry. High-heat mortar can also be used for applications in wood frame construction where an ASTM E136 non-combustible sealant is required, such as sealing around vents, pipes, ducts and chimneys at ceiling and floor level prior to the application of drywall products.