How a central Ohio year wears on a Gahanna chimney
Central Ohio gives a chimney two very different jobs across the year, and both leave a mark. Through the long heating season the flue is carrying the byproducts of every fire, and on a wood-burning chimney that means creosote, the tarry, flammable residue that condenses on the cool upper flue walls and builds up layer by layer until it is thick enough to catch fire. A Gahanna household that burns regularly through the winter can lay down a surprising amount of creosote in a single season, especially when the wood is not well seasoned or the fires are kept smoldering and slow rather than hot and clean. That buildup is the single most common reason we recommend a yearly sweep here.
Then comes the off season, and a different enemy. Central Ohio runs through dozens of freeze and thaw cycles every winter, and water is the agent of nearly all the masonry damage we see. Rain and snowmelt soak into a porous crown, a cracked cap, or open mortar joints, then freezes overnight and expands, prying the crack a little wider each time. By spring a hairline crack in the crown has become a real gap, the mortar has begun to spall, and water that used to run off the chimney is now running into it. The leak that shows up as a damp ceiling near the chimney in March was very often created by a crown crack the previous fall, which is why we are so insistent on catching these defects while they are still small and cheap to seal.