The Majestic DuraPlus 8" Square Ceiling Support Box is a premium triple-wall chimney support component designed to provide a secure transition through flat, vaulted, or cathedral ceilings in wood stove, fireplace, and all-fuel chimney systems. Featuring advanced ceramic blanket insulation and an insulating air space, the DuraPlus system keeps the exterior cooler while maintaining a strong, efficient draft. This chimney support box minimizes hot spots, enhances chimney fire safety, and protects both the venting system and surrounding building materials for long-lasting, reliable performance.

Engineered for continuous operation at flue gas temperatures up to 1000°F, the Majestic DuraPlus Square Ceiling Support Box exceeds rigorous UL 103HT safety standards, including one hour at 1400°F and three 2100°F chimney fire tests. Its durable construction delivers dependable support, code-compliant installation, and exceptional performance for modern residential all-fuel chimney venting systems.

• Heavy-Duty Square Ceiling Support Box: Designed for Majestic DuraPlus 8" triple-wall chimney systems, providing a secure and code-compliant support point for wood stove, fireplace, and all-fuel chimney installations.
• Compatible with Multiple Ceiling Types: Ideal for flat, vaulted, and cathedral ceilings, offering versatile installation options in residential chimney venting systems.
• Supports Long Chimney Runs: Engineered to support up to 35 feet of DuraPlus chimney, delivering exceptional structural stability and reliable performance.
• Integrated Starter Section: Features a built-in starter section for quick installation, proper chimney alignment, and a secure twist-lock connection.
• Durable Black Finish: The painted black square ceiling support box provides corrosion resistance and a clean, professional appearance that complements interior installations.
• Trim Collar Included: Includes a trim collar for a finished look while concealing ceiling openings for a neat installation.
• Adapter Compatible: Designed for use with DVL and DuraBlack adapters, allowing seamless integration with compatible stove pipe systems.
• UL 103HT Listed: UL Listed to UL 103HT (MH7399) for trusted safety, high-temperature performance, and code-compliant installation.