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A coal-era chimney serving a modern furnace?
- A pre-war house whose stack once served coal heat
- A furnace or boiler venting into old, oversized masonry
- Crumbling joint material inside the flue, visible only on camera
Why it happens in Pennsylvania: No state's chimneys are more shaped by coal. Pennsylvania's pre-war flues were sized and used for coal heat, and decades of sulphurous exhaust ate mortar from the inside, so the classic find is a flue whose inner face is far worse than its exterior suggests, in a stack shared with the heating plant.
What fixes it, and what it costs
Coal exhaust spent decades attacking these flues from the inside, and the conversion to gas made them oversized and cool-running: condensation finishes what the coal began. The camera tells the truth the exterior hides, and the repair is a correctly sized liner in the affected flue: it fixes the draft, the condensation and the deterioration in one move.
- Stainless liner, insulated, full height
- $2,500–$6,000
- Stainless for a stove or insert
- $1,800–$4,000
