The HT-10 chimney system is being touted as the first and only prefabricated, Class-A chimney capable of installation with zero clearance to combustibles. The system consists of a series of 2-foot-high by 16-inch-square boxes with interlocking joints that are sealed with a fire-rated adhesive caulk. At the core of each box is a 24-gauge stainless steel liner that's surrounded by a 1/4-inch-thick, high-density ceramic fiber insulation that will contain temperatures up to 2,100°F. Next comes a 2-inch layer of mineral wool, followed by a 1-inch-thick, highdensity calcium-silicate refractory board. Inside the house, the refractory board can be drywalled, painted, or wallpapered; on the outside it can be clad with stucco, brick, stone, or wood veneer. Three corbeling designs are available to