What a Fairfield County winter does to a Lancaster stack
Lancaster sits in the rolling country where the central Ohio plain starts breaking up into the hills, and the weather here is rough on brick. Cold, wet air settles in among the ridges, daytime sun gives way to hard overnight freezes, and that back-and-forth is what does the slow, patient damage to a chimney. Brick and mortar drink water like a sponge, soaking up rain and melting snow, and when the soaked masonry freezes, the water locked inside swells and shoves the material apart from within. One winter barely leaves a mark. Run a Lancaster chimney through fifteen of Ohio's freeze-and-thaw seasons and you get the flaking brick, the joints you can rake out with a screwdriver, and the split crowns that fill our spring calendar.
The second force is simply how hard these chimneys are asked to work. Wood heat runs deep around Lancaster and out through the hill country toward Hocking County, where firewood is close at hand and a wood fire is a practical way to beat back a long, cold season. A household that burns most evenings pushes a great deal of smoke up the flue, and smoke is where creosote is born. The cooler and slower a fire is allowed to smolder, the heavier the tar it lays down on the flue walls, and a flue carrying a load of that residue is the leading cause of a chimney fire. So the chimney is squeezed from two directions at once. Water bores in from outside through the freeze-thaw grind while creosote piles up inside from steady use, and a stack that goes a few winters with no sweep and no scan is quietly building both troubles at the same time.