What a southwest Cleveland winter does to a chimney
Strongsville sits where the lake-effect snow machine off Lake Erie meets the higher, colder ground of the inland suburbs, and that combination is hard on a chimney. We get long stretches of deep cold punctuated by brief thaws, and that back-and-forth is the single most destructive force a masonry chimney faces here. Water soaks into the brick and the mortar joints during a thaw or a wet spell, then freezes hard when the temperature drops, and the ice expands and pries the masonry apart a little more with every cycle. Over enough winters the face of the brick spalls, the mortar joints open, and the crown at the top develops the cracks that let still more water in.
Inside the flue, the cold drives a different problem. A fireplace or wood stove worked hard through a Cuyahoga County winter lays down creosote, the tarry residue that condenses out of woodsmoke, and the colder the flue runs the faster that residue builds. A flue that has not been swept since the previous heating season can carry enough creosote to feed a chimney fire, and the long burning season here means local chimneys accumulate it faster than chimneys in milder places. This is why we press homeowners to have the chimney swept and looked at before the heating season rather than after the first scare.