Stovepipe and Chimney Basics: Single-Wall, Double-Wall, Class A and Liners

A wood stove venting system has two parts: the connector (stovepipe) that runs from the stove to the ceiling or wall, and the chimney that carries smoke out of the house. They are different products with different listings and rules.

On this page

1. The connector: single-wall or double-wall stovepipe
2. The chimney
3. Size and height
4. Before you buy parts
5. Sources

The connector: single-wall or double-wall stovepipe

• Single-wall pipe needs the most room. Building officials often reference NFPA 211’s 18 inches to combustibles for single-wall connector pipe, reducible only with approved protection (Maine State Fire Marshal / NFPA-based standards).
• Double-wall (reduced-clearance) pipe is listed for smaller clearances, which are printed on the product’s listing.
• Pipe type can change the stove’s clearances too. The Drolet Escape 1500’s U.S. rear clearance is 13 in with single-wall pipe but 6 in with double-wall (Drolet).

Stovepipe is a connector only. It stops where the system passes through a ceiling, wall or roof, where a listed chimney takes over (typically via a listed ceiling support box or wall thimble).

The chimney

• Factory-built (Class A) chimney: insulated metal chimney listed for solid fuel. Drolet’s Escape stoves call for chimney listed to UL 103 HT (2100 °F) in the U.S. (Drolet). The chimney’s own listing sets its clearances and support requirements.
• Masonry chimney: must be sound and correctly sized; often needs a liner.
• Liner: a metal liner inside a masonry chimney. Inserts typically need one. The Osburn 1700-I insert calls for a liner listed to UL 1777 with a minimum height of 12 ft (manual).

Size and height

Match the flue diameter in the manual: the Escape stoves have a 6 in flue outlet and call for a 6 in chimney at least 12 ft tall (Drolet). Don’t reduce pipe size below the stove’s outlet unless the manual allows it.

Before you buy parts

1. Read the stove manual’s venting section.
2. Use one manufacturer’s listed system for the chimney, and follow its installation guide.
3. Get a permit if required, and have the system inspected.