Flue Requirements for a Wood Burning Stove

Damper

• All wood stoves are required to have a damper on the vertical, single wall flue pipe directly above the wood burning stove. The damper allows warm exhaust to exit through the chimney and prevents air from back drafting into the stove when not in use.

Flue Connections

• Pieces of the flue must connect through interlocking mechanisms that are air tight. If interlocking sections are not used, the flue pieces are required to be installed with fire caulking (2,000 degree Fahrenheit caulk) at all junctions and three screws to hold the sections together. The pieces that are tapered inwards should be stalled with the taper down towards the wood burning stove to prevent moisture from leaking out through the joints of the flue sections.

Pitch of the Flue

• The horizontal flue section that connects to the chimney is required to pitch 1/4 inch per foot back toward the wood burning stove. This allows for proper drainage of condensation and prevents back drafts.

Flue Pipe Diameter

• The flue pipe should be the diameter of the flue connector on the wood stove, typically 6 to 8 inches. It is not allowed to decrease the diameter of the pipe with a reducer. This creates poor ventilation and can drastically reduce performance as well as contribute to back drafting. Always follow the manufacturer's specific guidelines on flue sizing and length restrictions and installation methods.