DuraVent - DuraPlus 8" Inner Diameter Square Ceiling Support Box

Save $51.25
DuraVentSKU: 8DP-CS11

Regular price$204.98 Sale price$256.23
Flash Sale is ON! Free Shipping & Returns on All Orders. Get 15% off with the Code: FLASH15 for purchase over $199 and 19% off with the Code: FLASH19 for purchase over $8999. Best Deal Ever! Need Help? Call 800-466-4712 or mail us at sales@belleflame.com
Size: 11"
⛟ Estimated Delivery Date: Between and to all states excl. Alaska & Hawaii.


Introducing the DuraVent DuraPlus 8" Square Ceiling Support Box – your essential companion for stove safety, efficiency, and peace of mind. This ingeniously crafted support box is your first line of defense against the elements, ensuring that your chimney operates at peak performance while safeguarding your home.

Designed with excellence in mind, the DuraPlus Ceiling Support Box is the epitome of quality and reliability. Whether you have flat, vaulted, or cathedral ceilings, this support box has you covered. Its sleek black finish not only adds a touch of sophistication but also complements any decor seamlessly. What truly sets it apart is the integrated Starter Section, simplifying installation and ensuring a snug fit.


  • Enhanced Safety: DuraPlus is engineered with a fire-safe triple-wall construction that remains cool on the outside while maintaining a hot draft on the inside. It's your dependable shield against chimney fires.
  • Optimal Efficiency: With two insulating layers and a ventilated air space, this support box boosts stove efficiency, reducing heat loss and ensuring even heating throughout your home.
  • Versatile Compatibility: Whether you have a flat, vaulted, or cathedral ceiling, the DuraPlus Square Ceiling Support Box is designed to seamlessly integrate into your space.
  • Built to Last: Crafted from high-quality stainless and galvanized steel, this support box is built to withstand the test of time and elements, backed by a limited-lifetime warranty.
  • Hassle-Free Installation: Thanks to the precision twist-lock connection, installation is a breeze, ensuring a secure and reliable fit.
  • UL Listed: Rigorously tested and UL Listed to UL 103HT (MH7399), providing you with the utmost confidence in its safety and performance.
  • Ceiling Pitch Table: Easily determine the right size support box for your ceiling pitch using our convenient Ceiling Pitch table.


  • Use with flat, vaulted, or cathedral ceilings.
  • The Square Ceiling Support Box is painted black.
  • Starter Section built-in.
  • Supports up to 35’ of DuraPlus Chimney.
  • For adapters, see DVL and DuraBlack section.
  • Trim included.
  • Refer to the Ceiling Pitch table to determine the size of the support box needed.

Materials and Construction:

  • .016” 430 stainless steel outer wall
  • .016” 430 stainless steel inner liner.
  • .018” galvanized steel outer wall.
  • .018” aluminized steel intermediate liner.
  • Insulated layers plus ventilated air space.
  • Locks tightly with a precision twist-lock connection.


Model 8DP-CS11 8DP-CS24 8DP-CS36
Diameter 8" (inner) 8" (inner) 8" (inner)
Dimension 11" (A) x 18.25" (W) 24" (A) x 18.25" (W) 36" (A) x 18.25" (W)
Clearances 2" clearance to combustible.
Listings UL Listed to UL 103HT (MH7399).
Warranty Limited-lifetime warranty
Ceiling Pitch Table
DuraBlack DVL USE
0/12-4/12 0/12-6/12 11" Support Box
5/12-9/12 7/12-13/12 24" Support Box
10/12-14/12 14/12-20/12 36" Support Box


About the Manufacturer:

Consistently the first to market with new innovations in venting systems, DuraVent has captured a leadership position in emerging markets. DuraVent has patents for several products and continues to design safe and technologically advanced venting.The company’s research into solving problems with corrosion, when biofuels such as corn are used, led to the break-through patent for PelletVent Pro.

Order Confirmation:

Upon placing your order, you will promptly receive an email confirmation. Subsequently, we will conduct a thorough inventory check to ensure all items are in stock and available for immediate shipment. If your order aligns with the advertised delivery timeframe, we will promptly process it for shipment to our warehouse. In cases where the expected delivery time extends beyond the advertised timeframe, we will reach out to you via email and/or phone for confirmation.

Order Shipment:

Within one business day of your item being shipped, you will receive an email confirmation containing a tracking number. If you do not receive tracking information within six business days of placing your order, please don't hesitate to get in touch with us for assistance.

Estimated Time of Arrival:

Our typical delivery timeframe ranges from 2 to 10 business days. Custom-made products generally require 3 to 5 weeks for delivery. If the expected delivery date for your order would fall outside of the advertised 2-10 business day time frame, our customer service team will contact you to ensure your agreement with the revised timeline.

Covered Areas:

Please note that all estimated delivery dates and shipping costs advertised on our website apply exclusively to the Contiguous United States. For inquiries regarding shipping to Hawaii or Alaska, kindly reach out to our customer service team. While we do not offer direct shipping to Canada, we are more than willing to ship your order to the freight carrier of your choice.


It is very important that you inspect the packaging of your items when they arrive and check if you received all boxes listed on the delivery receipt. If you notice any damage or shortage of packages, you must make note of it on the bill of lading, take pictures, and refuse delivery. Your note should say "refused due to damage". You must also take photos of all sides of the box and send them to us within 2 days. If there are no damages visible before opening the box, you must note "subject to further inspection may contain concealed damage". If you notice any damage after receiving the delivery, do not throw the box away, and contact us with the photos. After we receive information from you about the refused delivery or concealed damage, we immediately initiate a claim with the shipping company or with the manufacturer. After the claim is fully processed, we ship all replacements at absolutely no cost to you.

Cancellations & Refunds:

We offer free order cancellations before the shipping label or Bill of Lading is generated, or prior to the commencement of production for custom orders. Please note that custom-made items are not eligible for refunds once production has begun. To be eligible for a return, the item must be unused and in its original condition, with all packaging intact and in perfect condition. Orders delivered outside of the United States are not eligible for refunds. If your order arrives damaged, please refer to the "Damages" section. Our refund policy extends for 30 days. If 30 days have elapsed since your purchase, regrettably, we cannot process a refund. Prior to returning an item, please contact us to discuss shipping details. All refunds will be credited to the original credit card or PayPal account used for the purchase, within two days of receiving the returned items at our warehouse.

Please contact sales@belleflame.com for any questions regarding shipping time.

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