KOS Flue Cement is a high temperature (to 1250° C) ready mixed fireproof mortar paste , designed for the safe installation/jointing of Type A1 (BSEN1857) concrete flue liners (previously known as class 1) for use with domestic fires and stoves e.g. coal, wood burning or gas (including flame effect). KOS FLUE CEMENT may also be used as a general purpose fire cement in most applications where direct flame contact occurs.