In Glastonbury, CT, Level One inspection found the fireplace venting system is coated with a solid stage 3 creosote glaze. Stage 3 creosote is very hard, dense and combustible, It's also the only form of creosote not removable via a standard sweep. This fireplace chimney needs a very aggressive cleaning with steel whips, 5-ft steel rods, heavy duty drill and rotospun off at 1400 RPM.