Double Wall Flue Pipe Clearance

The minimum installation clearances for certified double wall flue pipes are much less than those for single wall pipes.

Double wall flue pipe clearance. Metal flue fire clearance requirements single wall metal pipe flues gas fired equipment. For example a single wall stove pipe requires 18 inches of clearance from ceilings or walls. Double wall stovepipe is used when you don t have 18 or more clearance from combustibles. Dvl double wall stovepipe completes the venting system when used with one of duravent s chimney products such as duratech duraplus or duraplus htc.

Dvl s double wall air insulated design reduces clearances to combustibles from 18 in. One of the fire safety features of double wall type b gas vent is that its outer wall insulated by the airspace beneath it requires only 1 clearance to combustible material in the structure. Double walled black stovepipe must be kept 6 inches away from combustible wall material as it connects with the chimney pipe. We discuss fire safety fire clearances and other gas appliance venting details for b vent chimneys.

Once these clearances are met you must convert your stove pipe to class a chimney pipe for proper venting of your stove. For single wall stovepipe the clearance space remains 18 inches. To 6 in the closest clearance to a wall of any connector pipe. This one is the sealed type.

Most of the double wall stove pipe allows for 6 clearance from wall combustibles and 8 from ceiling combustibles. 9 is a typical clearance between a gas fired boiler or furnace flue connector and combustibles. A straight up double wall flue pipe assembly. Also the maximum length of a double wall flue pipe assembly may be greater than is permitted for a single wall pipe.

Double wall stove pipe on the other hand requires only 8 inches of clearance from the ceiling and 6 inches from a wall. Using a heat shield on a single wall stovepipe allows you to reduce the clearances from 18 to 6 to the wall and 9 to the ceiling. Type b vents ceiling floor wall clearances b vent clearances to combustibles clearance distances for a b vent to combustible materials in floors walls ceilings attics roofs. Double walled or close clearance stove pipe is used to connect your stove to the chimney this pipe has a clearance of only 6 to combustible materials and keeps flue gases warm for better draft.

This article series describes b vent metal chimneys used for gas fired appliances. When combining lengths remember to subtract 1 5 from each to account for overlap.