While the exteriors of chimneys are built to withstand the elements, the interior chimney components are designed to be exposed to heat – not moisture. Because of this, even the smallest amounts of water that enters your chimney can cause serious damage. Being able to identify the signs of a leaky chimney can help you know when it is time to call the chimney sweep for repairs – and help minimize damage to your fireplace.

Signs of a leaky chimney

snow on the groundMost homeowners believe a leaky chimney presents itself as water in the firebox or flue. While this is the case for some leaks, the size and accessibility of the chimney often result in leaks causing serious damage way before spotted. The following are eight signs that may indicate you have a leak in your chimney system.

  1. Water in the firebox
  2. Condensation on glass fireplace doors
  3. Sound of dripping water in the chimney
  4. Mold or mildew growth in the fireplace
  5. Rust on the damper or other metal fireplace components
  6. Visible water, leaks, or stains on walls and ceilings surrounding the chimney
  7. Cracked or spalled interior or exterior masonry
  8. Significant musty or dank odor in the fireplace, especially after rain

What causes chimney leaks?

Each leaky chimney is different. Because of this, there is no easy answer to what causes a chimney leak. While a chimney inspection by a certified chimney sweep is often needed to identify the source of a leak. The following are four of the most common causes of water entry into your chimney.

  1. Chimney cap – The chimney cap is a metal hood that covers and protects the top of the flue. If it is damaged or missing, moisture from rain, snow, and even sprinklers can drain directly into the flue and fireplace.
  2. Chimney crown – The chimney crown is a stone or masonry slab that seals the top of the chimney and surrounds the flue. Incorrectly built chimney crowns are flat; this can cause water to pool on the crown and allow cracks and holes to form.
  3. Flashing – Flashing is created when strips of metal and waterproofing materials are layered to seal the joint between the roof and the chimney. Overexposure to the elements, incorrect installation, or roof repairs can all cause flashing to become loose and lose its watertight seal.
  4. Masonry – Cracks and holes in the masonry of the chimney can allow water to get in. This is often seen after a long winter, when the freeze-thaw cycle has damaged the masonry.

A chimney leak can cause damage long before the first water drops appear in your fireplace. By knowing the signs of a leaky chimney, you can help prevent moisture damage from negatively affecting your fireplace system. For more information about the signs of a leaky chimney or to schedule your chimney inspection, contact the experts at Coopertown Services today!