How the Sound and the cold work on a Stamford chimney
Living this near salt water has its rewards, but it is hard on a chimney. The humid air rolling in off Long Island Sound keeps Stamford masonry damper than it would be further inland, and damp brick is brick that decays. Moisture soaks into the mortar joints, settles into the porous face of older brick, and lingers in the shaded chimneys on the wooded lots north of the parkway long after a sunnier stack would have dried out. That standing dampness is the quiet engine behind most of the masonry trouble we are called to fix in this part of Fairfield County.
Then the cold turns that moisture into a wrecking tool. When a damp Stamford chimney freezes, the water trapped inside the brick and the mortar expands as it turns to ice, prying at every pore and hairline crack from the inside. Thaw it, freeze it again, and repeat that cycle through a Connecticut winter, and the face of the brick begins to flake away while the mortar joints open and crumble. A crown that was sound in October can be cracked by March. This is why a chimney here cannot simply be swept and forgotten. The water has to be kept out, or the freeze will take the masonry apart one winter at a time.