Is Mother Nature giving your chimney a frost wedgie?
The same process that creates potholes on our Minnesota roads is acting on your masonry chimney. It's true and the principle is quite simple. See my little diagram, right.
The easiest way to keep your brick or stone chimney in good condition is to keep water from working its' way into the cracks that inevitably develop on the surface of your chimney. The majority of the chimneys I inspect that have damage have one major flaw in common. They lack an overhang to encourage water to say away from the column of the chimney. Just as homes typically have overhangs at the eaves so should chimneys.
Most of the masonry and stone chimneys we repair in the Minneapolis area receive a new wash cap, some brick resetting and general tuck pointing. Some chimneys have to be completely rebuilt. The main determining factor in how much damage we find is how long the homeowner has let water do its' thing through the freeze-thaw cycle on their chimney.