Duravent Stove Pipe DuraTech Round Ceiling Support Box DISC

The 5DT-RCS and 5DT-CS24 both support up to 60 feet of DuraTech chimney and both provide the required structural support and fire separation at ceiling penetrations using a built-in twist-lock connection. The primary differences are profile shape, trim collar inclusion, and outer wall material. The 5DT-RCS has a round profile with a galvanized steel outer wall and its trim collar is sold separately as the 5DT-TCR. The 5DT-CS24 has a square profile with a black painted exterior and includes a 2-inch wide trim collar. The choice between round and square support boxes is primarily driven by the preferred ceiling penetration profile and aesthetic for the specific installation, as both perform the same structural and fire separation functions.

DuraVent offers the round ceiling support box trim collar — the 5DT-TCR — as a separate purchase for the 5DT-RCS, unlike the square support box which includes a trim collar. The trim collar provides the decorative finished ring visible at the interior ceiling surface around the support box, covering the rough framing opening and providing a clean professional appearance at the penetration point. Ordering the trim collar separately allows flexibility in selecting the correct trim size and finish for the specific installation, and ensures the trim collar can be replaced independently if needed without replacing the entire support box. The 5DT-TCR must be ordered alongside the 5DT-RCS to complete the finished ceiling penetration appearance.

The 5DT-RCS ceiling support box is an interior installation component that is installed within the building structure at the ceiling framing level — it is not exposed to the outdoor weather environment in the way that the exterior sections of the chimney pipe above the roofline may be. Galvanized steel outer wall construction is appropriate for interior installation components because galvanized steel provides adequate corrosion resistance in the protected indoor environment of a ceiling framing assembly. The stainless steel outer wall option available on the DuraTech pipe sections is recommended for outdoor weather-exposed applications, while the galvanized outer wall construction of the support box is suited to its permanently interior location within the building structure.

The bottom of the DuraTech round support box is designed for the DuraTech chimney system's twist-lock connection interface. DVL double-wall close-clearance connector stovepipe and DuraBlack single-wall connector stovepipe use different connection geometries than the DuraTech twist-lock interface, and a dedicated adapter is required to provide the mechanical transition between those stovepipe systems and the DuraTech support box connection at the bottom. The appropriate adapter must be selected to match the specific type of stovepipe — DVL or DuraBlack — being used to connect the appliance to the chimney. The adapter is not included with the 5DT-RCS and must be ordered separately.

Yes. The 5DT-RCS is confirmed as suitable for both flat and cathedral — A-Frame — ceiling installations. In a cathedral ceiling application the ceiling framing members are angled rather than horizontal, and the round support box must be installed through the angled ceiling framing to allow the chimney pipe to pass through vertically. The DuraTech installation instructions provide specific guidance on the correct installation technique for ceiling support boxes in cathedral ceiling configurations, including how to frame the opening and mount the support box to maintain the required chimney pipe alignment and clearances through the angled ceiling assembly.

The 5DT-RCS works alongside the straight pipe sections — including the 5DT-06SS, 5DT-09SS, 5DT-12SS, 5DT-24SS, 5DT-36SS, 5DT-48SS, and 5DT-60SSCF — that connect to the twist-lock at the top of the support box and build the chimney run above it. The 5DT-TCR round trim collar is required to finish the ceiling appearance at the support box location. The 5DT-IS Attic Insulation Shield fits over the support box when the chimney passes through an attic above the support level. The 5DT-FRS Firestop Radiation Shield manages any intermediate floor or ceiling penetrations above the support box level where a second support box is not used. Roof flashing, storm collar, and chimney cap complete the system at the exterior roof termination.