DuraPlus Square Ceiling Support Box & Trim Collar

The Square Ceiling Support Box is designed for use with flat, vaulted, or cathedral ceilings, providing a secure and stable foundation for your chimney system. Finished in sleek black paint, this support box can handle up to 35 feet of DuraPlus Chimney. It features a built-in starter section for easy installation and comes with a trim for a clean, finished look. To ensure proper sizing, refer to the Ceiling Pitch table to select the appropriate support box. Available in 6" and 8" diameters. Additional DuraPlus Info: DuraPlus is engineered to maintain a cooler exterior while promoting a hotter draft inside, enhancing stove efficiency and ensuring a fire-safe design that safeguards both the chimney and the surrounding structure. This triple-wall chimney features two layers of insulation: a ceramic blanket and an air gap. The ceramic blanket insulation is securely positioned, preventing the hot spots often caused by loose-fill insulation types. In the event of a creosote fire, the compressible insulation allows the chimney liner to expand outward radially. Built to withstand continuous operation at 1000°F flue gas temperatures, DuraPlus meets the rigorous UL standards, including one hour at 1400°F and three ten-minute chimney fire tests at 2100°F.