Duravent Stove Pipe DuraTech Attic Insulation Shield, 5"

DuraVent's DuraTech installation instructions specify that the Attic Insulation Shield must be used in all installations that pass through an attic regardless of whether the attic is insulated or not. Even in an uninsulated attic, debris, dust, sawdust, wood shavings, and other combustible materials can accumulate around the chimney pipe over time from the building structure and normal use of the attic space. The 5DT-IS creates a protected clearance zone around the pipe that prevents any such material from coming into contact with the heated chimney surface, and the mesh sleeve at the top prevents material from entering the shield from above. The requirement applies universally to all attic penetrations because the risk of debris accumulation exists regardless of whether insulation has been installed.

The 5DT-FRS and 5DT-IS are companion components that work together in attic installations. The 5DT-FRS is the primary penetration component that is installed first at the attic floor level — it centers the pipe within the framing opening and provides the required fire separation at the floor or ceiling penetration. The 5DT-IS is then installed over the 5DT-FRS in the attic space, fitting around the 5DT-FRS as a base and extending upward with the collar and mesh sleeve to create the insulation exclusion zone around the chimney pipe through the attic height. The two components serve distinct but complementary functions — the 5DT-FRS manages the penetration fire separation, and the 5DT-IS manages the attic insulation and debris exclusion above that point.

Yes. The 5DT-IS is designed to fit over either the 5DT-FRS Firestop Radiation Shield or a DuraTech support box at the attic floor level. In installations where a support box is used at the attic penetration point rather than the firestop radiation shield — for example, where the chimney is also being structurally supported at that level — the 5DT-IS fits over the support box to provide the attic insulation and debris exclusion function above the support box. The choice between using the 5DT-FRS or a support box at the penetration point is determined by whether structural chimney support is needed at that level; the 5DT-IS requirement applies in either case.

The mesh sleeve at the top of the 5DT-IS Attic Insulation Shield prevents attic insulation particles, blown insulation fibres, dust, and debris from entering the interior of the shield enclosure from the open top. Without the mesh sleeve, loose materials present in the attic space could fall or migrate down into the shield enclosure from above and accumulate around the chimney pipe inside the protected zone, defeating the purpose of the shield. The mesh allows air circulation within the protected zone while physically blocking particulate material from entering. This is particularly important in attics with blown-in insulation such as cellulose or fibreglass, which can migrate over time and would otherwise work its way into any unscreened opening around the chimney pipe.

The 5DT-IS collar and base assembly provides a fixed height of protection above the attic floor level. In attics where the insulation depth is very high or the attic height is unusually tall, the installer should confirm with the DuraTech installation instructions whether additional measures are needed beyond the standard 5DT-IS to ensure the chimney pipe is adequately separated from insulation and debris across the full depth of the attic insulation layer. The primary concern is that insulation in contact with or very close to the heated chimney pipe surface in the attic represents a fire hazard, so the 5DT-IS and the clearance it establishes must be sufficient to keep all insulation material below the top of the shield enclosure away from the pipe.

A typical DuraTech 5-inch chimney installation passing through an attic requires the 5DT-FRS Firestop Radiation Shield or a support box at the attic floor penetration, the 5DT-IS Attic Insulation Shield installed over the 5DT-FRS or support box, and straight pipe sections such as the 5DT-09SS and 5DT-12SS to build the chimney run through the attic height from the penetration to the roof exit. At the roof, a roof flashing sized to the roof pitch, a storm collar, and a chimney cap complete the exterior termination. If there are structural obstructions in the attic requiring a chimney offset, the 5DT-E15KSS or 5DT-E30KSS elbow kits are used within the attic run, subject to the 30-degree maximum offset limit.