Cause #1: Rain Entering from the Top
Chimneys without covers are susceptible to rainwater falling directly into them. It’s important to install a chimney cover to not only keep rain out but also prevent birds, animals, and debris from entering. The primary benefit of a chimney cover is to keep the chimney clear because blockages can lead to CO poisoning.

Cause #2: Cracks in the Chimney Crown
The chimney crown, the cement part on top of the chimney, is designed to prevent rain and snow from entering around the flue liners. When cracks develop in the crown, water can seep through them and cause leaks. It is crucial to address these cracks to maintain a watertight seal. Learn more about chimney cleaning to keep your chimney in good condition.

Cause #3: Leaks due to Condensation
Gas fumes, especially at lower temperatures, contain a significant amount of moisture. In an oversized or cold chimney, these fumes can condense on the inside, leading to constant moisture on the bricks. The implementation of a chimney liner can effectively resolve this issue and prevent further leaks.

Cause #4: Problems with Chimney Flashing
Flashing is used to prevent water from entering where the brick structure intersects with the roof or comes close to it. If the flashing is not properly sealed, there is a gap that water can easily flow through. Oftentimes, aluminum flashing is used and sealed with waterproof “stuff,” such as tar. While tar is not the ideal choice, it is frequently used for this purpose.

Addressing these common causes of chimney leaks is crucial to maintain a dry and safe chimney system. If you’re facing any of these issues, it’s recommended to consult professionals for appropriate repairs and solutions.