UL3652GT-3 36"X 52" GRAY BLOCK STOVEBOARD | A HY-C stove board/hearth extender will protect the floor from heat and sparks in front of your fireplace or beneath, in front and around a wood burning stove. Constructed of embossed printed steel over 1/2 in thick specially formulated fiber board which is non-combustible, it may also be used as a wall shield to protect walls from intense heat.