Kit for an External Chimney for a Garage

The diameter is measured on the inside of the (inner) pipe. Common sizes are 4", 6", and 8", depending on your appliance. A 4" liner is typically used for gas appliances and some pellet stoves. Most wood stoves use a 6" internal outlet, while larger stoves or open fireplaces may need 8". Check your appliance manual or look at the round collar where the flue connects.

Determine the Height of the Stove Pipes

Take a measurement from the stove up to the middle of the opening in the wall.

You only need to be close with your measurements here, not exact. Our black stove pipes cannot be cut to size so you will need one of our telescoping lengths to complete your installation. This gives you lots of "play" in your measurement.

Stove pipes must be kept at least 18″ away from any combustible materials.

 

For the vertical-rise options, the stove adapter and 90-degree elbow together provide approximately 11 inches of vertical rise. They are not used when the stove exits horizontally from the rear.

Between them, you can install:

• A variable length pipe (strongly recommended): 38–70 inches (effective vertical length: 36–68 inches). Easy to install.

• A fixed straight length:

  • 12 inches – effective length: 10 inches

  • 18 inches – effective length: 16 inches

  • 24 inches – effective length: 22 inches

Fixed pipe lengths provide less adjustment. The wizard combines them with a telescoping section where adjustment is required. Do not cut any component unless its product instructions specifically allow it.

How to Choose Your Wall Type and Thickness

Measure the complete wall thickness from the finished inside surface to the finished outside surface.

• Select combustible if the wall contains wood framing, timber or other combustible material. Most US exterior walls contain wood framing and are combustible.
• Select non-combustible only for walls made entirely from materials such as brick, concrete, block or stone.
• For a non-combustible wall, the Class A pipe must extend at least 3 inches into the room.
• For a combustible wall, single-wall stovepipe must remain at least 18 inches from the wall. The transition to Class A pipe must take place before this clearance zone.
• Stovepipe must never pass through the wall. Only insulated Class A chimney pipe may enter the wall thimble.

The wizard accounts for the wall thickness, the inside clearance, approximately 4 inches provided by the tee branch and an adjustable outside wall distance of 2–7 inches.

The standard wall thimble fits walls from approximately 6–10 inches. It can be shortened for thinner walls. For walls thicker than 10 inches, please contact us before ordering.

How much chimney is above the last support (roof edge or wall band)? 

You need to support the flue if the free end becomes too long and requires additional support. We recommend using a telescopic support if the free end From last wall strap to the cap) is between 5 and 10 feet.