At a glance
- Type: Ceiling support box, part of the DuraTech chimney system
- Diameters: 5", 6", 7" and 8"
- Listing: c-UL-us listed to UL 103 HT
- Clearance: 2" to combustibles
- Made by: DuraVent
Description
Supports the chimney at the ceiling and keeps the required clearance through it. DuraTech 5 to 8 inch is DuraVent's double-wall, insulated all-fuel chimney, c-UL-us listed to UL 103 HT with a 2-inch clearance to combustibles.
Specifications
Dimensions
| Part | Diameter | Style | Finish | Weight |
|---|---|---|---|---|
| 5DT‑FCS | 5" | Flat Ceiling Support Box | — | 6.0 lb |
| 5DT‑RCS | 5" | Round Ceiling Support Box | — | 4.1 lb |
| 5DT‑CS24 | 5" | Square Ceiling Support Box - 24" | — | 12.6 lb |
| 5DT‑CS36 | 5" | Square Ceiling Support Box - 36" | — | 17.0 lb |
| 5DT‑CS11‑2 | 5" | 11" Square Ceiling Support Box | — | 8.4 lb |
| 6DT‑SBRU | 6" | Support Box Rails | — | 1.5 lb |
| 6DT‑CS11‑2 | 6" | 11" Square Ceiling Support Box | — | 8.5 lb |
| 6DT‑CS24‑2 | 6" | 24" Square Ceiling Support Box | — | 14.2 lb |
| 6DT‑CS24IS‑2 | 6" | 24" Support Box with Insulation Shield | — | 14.3 lb |
| 6DT‑CS24R‑2 | 6" | 24"Reduced Ceiling Support Box | — | 12.6 lb |
| 6DT‑CS36‑2 | 6" | 36" Square Ceiling Support Box | — | 18.4 lb |
| 6DT‑CS36IS‑2 | 6" | 36" Support Box with Insulation Shield | — | 18.4 lb |
| 6DT‑FCS‑2 | 6" | Flat Ceiling Support | — | 7.8 lb |
| 6DT‑RCS‑2 | 6" | Round Ceiling Support Box | — | 9.4 lb |
| 6DT‑TCR‑2 | 6" | Round Support Box Round Trim | — | 1.9 lb |
| 6DT‑TC‑2 | 6" | Round Support Box Square Trim | — | 1.9 lb |
| 6DT‑CS24RIS‑2 | 6" | Support Box 24"Reduced with Insulation Shield | — | 12.7 lb |
| 7DT‑CS11‑2 | 7" | 11" Square Ceiling Support Box | — | 9.2 lb |
| 7DT‑CS24‑2 | 7" | 24" Square Ceiling Support Box | — | 18.8 lb |
| 7DT‑CS36‑2 | 7" | 36" Square Ceiling Support Box | — | 21.0 lb |
| 7DT‑FCS‑2 | 7" | Flat Ceiling Support | — | 8.4 lb |
| 7DT‑RCS‑2 | 7" | Round Ceiling Support Box | — | 5.9 lb |
| 7DT‑TCR‑2 | 7" | Round Support Box Round Trim | — | 2.1 lb |
| 7DT‑TC‑2 | 7" | Round Support Box Square Trim | — | 2.1 lb |
| 8DT‑CS11‑2 | 8" | 11" Square Ceiling Support Box | — | 9.8 lb |
| 8DT‑CS24‑2 | 8" | 24" Square Ceiling Support Box | — | 14.9 lb |
| 8DT‑CS36‑2 | 8" | 36" Square Ceiling Support Box | — | 21.0 lb |
| 8DT‑FCS‑2 | 8" | Flat Ceiling Support | — | 9.0 lb |
| 8DT‑RCS‑2 | 8" | Round Ceiling Support Box | — | 5.3 lb |
| 8DT‑TCR‑2 | 8" | Round Support Box Round Trim | — | 2.1 lb |
| 8DT‑TC‑2 | 8" | Round Support Box Square Trim | — | 2.1 lb |
Documents
Details
| System | DuraTech |
|---|---|
| Listing | c-UL-us listed to UL 103 HT |
| Clearance to combustibles | 2" to combustibles |
| Price basis | DuraVent 2026 list price (MSRP), effective July 1, 2026 |
Questions
What size do I need?
The appliance's own instructions set the chimney diameter; match it, and keep the whole chimney one diameter.
What clearance does it need?
2" to combustibles, per DuraVent's listing. Never fill the clearance space with insulation.
Can I mix DuraTech with other brands?
No. DuraVent's instructions require authorized DuraTech parts only, to keep the chimney listed.
Where are the installation rules?
In the documents above: supports, firestops, enclosures and chimney height are set by DuraVent's instructions, and the installer follows them.
Why is there no photo?
DuraVent images are being added; the part numbers and sizes on this page are from DuraVent's 2026 list.
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