Renovating a Chimney
New flue liners convert fireplaces for woodstove use.
Synopsis: The start of the wood-heating craze taught many homeowners that their old chimneys weren’t safe for a woodstove. This article explains how a tile liner can be added to an old brick chimney, a difficult but not impossible job.
Installing new flue lining in an old chimney is somewhat akin to digging a basement under a finished house — it’s not impossible, but it’s a lot easier to do beforehand, during the original construction. Unfortunately flue liners were invented a long time after many chimneys had been built, and the older the chimney, the greater the need for new liners. Cast from fire-clay or fireproof terra cotta, they provide a safe, effective exit route for smoke and combustion-related gases. Unlined chimneys are hazardous, ineffective and troublesome by comparison.
The chimney we had to work on was part of a common wall in a three-story Brooklyn row-house, built between 1860 and 1870. Although it served three fireplaces, we planned to eliminate the one on the third floor and convert the other two for woodstove use. This meant installing two separate flues in the chimney space, one for each stove. We decided to begin the job on the second floor, adding the first-floor flue sections at a later date.
Before starting a job like this, it’s important to know the type of stove to be used, because the location of the stove’s exit pipe determines where you install the thimble fitting in the new flue. I had decided on a Lange 6303A/B, a Danish woodburning model with an exit pipe that can be adapted to run from either the back or the top of the stove. I chose to use the horizontal exit, since this would allow me to install the thimble in the first flue section rather than…