The causes of a leaking chimney can be caused by many different factors. Here are 5 that we often find.

  1. Rain that is going straight inside the chimney from the top is a common cause of a leaking chimney. The simplest solution for this is the installation of a chimney cap. An uncovered chimney allows the rain to pour inside, especially during heavy rains. Aside from rain, a chimney cap protects the chimney from animals and birds that often nest inside of the chimney.
  2. There may be crack in your chimney crown that can allow water to enter. The chimney crown is the flat or beveled area that is found on top of your chimney. Chimneys can crack due to a shift in the structure or from freeze/thaw cycles. A cracked crown can be fixed, but should be done by a professional. If your chimney crown has a small crack, it may still need fixing to prevent it from getting worse. Water that enters in small cracks will freeze during the winter, thus expanding the cracks into a much bigger problem. There are coatings available to patch smaller cracks to prevent further damage. Coatings may not fix bigger cracks, so it is better to treat them early to prevent additional expense and hassle.
  3. Condensation causes water leaks from the inside out. The chimney should be lined with the correctly sized liner. Sometimes a liner can solve a leaking problem.
  4. Improper or deteriorated chimney flashing may also cause leaks. If there is a gap between the brick and the roof and it is not sealed, the water may get through and cause a leak. A professional chimney sweep can fix this.
  5. Leaking bricks can also be the source of water entering the home. This is similar to leaks from chimney crowns. You can waterproof your chimney, but make sure only high quality materials are used. During summer, the water that enters broken bricks will dry out, but during winter, the water can freeze, causing bigger and more expensive problems.