If you've noticed pieces of brick lying on your roof, in your gutters, or on the ground around your chimney, your chimney is probably spalling. This is one of the most common types of chimney damage we see in northeast Kansas, and it almost always starts with water.
Brick or stone spalling occurs when water has soaked into the brick and then freezes. This freeze cycle causes the water to expand which breaks the brick or stone apart. Spalling is much more prevalent from the roof up because more freeze/thaw cycles happen above the roof away from the protection of the house itself. Once bricks have begun spalling the damage will get exponentially worse every winter because the spalled surface allows even more water intrusion.
One thing to keep in mind is spalling doesn’t only happen on the outside of the brick where it is visible. The inside of the bricks can spall as well meaning that the damage is often more widespread than it would seem at first glance.
Spalling is easily preventable! We offer a clear sealant that prevents water soaking into good bricks. If spalling has already started this sealant is less effective than on good solid bricks but it will still be helpful to slow further deterioration. Another very helpful solution is to put an “umbrella” over the chimney to help keep the water off to begin with. This can be accomplished in the form of a proper crown or a full coverage cap. In the occasions where spalling has gone to far to fix it may be necessary to partially rebuild the chimney. Chimney rebuilds are usually only necessary from the roof up.