Glazed-on creosote is highly flammable and very difficult to remove from the chimney flue. Therefore, in extreme cases of glazing, very expensive chemical treatments may be required along with multi-phase cleanings, to remove the glazing from the liners. Another option to remedy the problem, which can be expensive as well, is to re-line the chimney with new liners. In minor or spotty cases of glazing, you may be able to use a self-use crystallized powdered treatment, during the use of your fireplace. Our sweep will let you know if you have any of this type of build up and to what extent at the time of cleaning. If the case is extreme, we do not recommend burning your fireplace, until the issue is resolved.