How to Retrofit a Chimney Flue for a Wood Stove

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When installing a wood stove into your fireplace, one of the most important considerations is how the stovepipe will interface with the chimney flue. Remove the damper to the chimney and insert a plate of sheet metal to act as a pan the stovepipe will go through.

This will keep the pipe sealed so you won’t get smoke back into your house. Make the sheet metal pan yourself and affix it to the opening of your chimney and the wood stovepipe with a few tools to retrofit a flue for the stove.

Remove the fireplace damper by taking off the cottar pin and lifting the damper out. Store it in a safe place so you can replace it if you decide to remove the wood stove. The stovepipe should already be in place in your chimney.

Measure the dimensions of the bottom opening of the chimney; measure the open space just 2 inches above the opening. Cut a piece of sheet metal the size of the opening, plus 1 additional inch on each side.

Notch the corners of the sheet metal about 1 inch, and at a 60-degree angle using the tin shears; bend the sides of the pan down to make a flange on each side.

Cut a hole in the centre of the sheet metal pan by making a hole with a screwdriver and hammer and cutting the hole slightly larger than the stovepipe diameter with the tin shears.

Insert the metal pan into the opening of the chimney up and around the stovepipe. Use masonry nails to hammer through the inch side panels you made on the sheet metal pan and into the masonry joints to secure it.

Seal the metal pan with the silicone caulk to the stovepipe and around the edges of the pan where it meets the masonry.