DuraTech Stainless Steel Square Support Box - 11" w/Flue Extension

The DuraTech Stainless Steel Square Support Box is a versatile, high-strength solution for supporting DuraTech chimney systems in both flat and cathedral (A-frame) ceiling installations. Designed to fit between standard 16" on-center joists, it is also ideal for short attic spaces and most manufactured home applications. This updated version features important product improvements to simplify installation and enhance performance, including a built-in pass-through radiation shield and an integrated flue extension that allows the stovepipe to connect directly to the ceiling support—eliminating the need for a separate chimney adapter.

Engineered to provide a secure, positive connection between the support box and DuraTech chimney pipe, this model incorporates a built-in twist-lock feature for added stability and can support up to 60 feet of chimney pipe. The integrated adapter is compatible with both single-wall and double-wall stovepipe, making it a flexible and dependable choice for a wide range of venting applications. Finished in black for a clean, finished appearance, it includes a 2" wide trim collar. Support box height is 11".

DuraTech Additional Info:

Featuring thermal blanket insulation between dual walls, DuraTech delivers top-tier safety and performance. It maintains a cool outer chimney wall while ensuring high flue gas temperatures for optimal draft. The inner wall is 25% thicker than those in competing chimneys, providing an extra layer of safety. With no need for locking bands or mechanical fasteners, DuraTech’s sleek 1" wall design allows for easy installation through 16" on-center framing. For tight spaces, a Reduced Clearance Square Ceiling Support Box is available (6" diameter DuraTech only). Engineered for continuous operation at 1000°F flue gas temperatures, DuraTech meets rigorous UL standards, including testing at 1400°F for one hour and three ten-minute chimney fire tests at 2100°F.

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