A chimney leak is a serious issue that can cause extensive chimney damage that not only compromises its safety and efficiency but can also jeopardize its structural integrity if it is not resolved timely. Chimney leaks are not always obvious, so you can still have leaks even though you don’t see a puddle or dripping water in the fireplace. If you notice one or more signs of a chimney leak, schedule an appointment with a Certified Chimney Sweep® to find the source of your chimney leak quickly.
Do you have a chimney leak? If you notice one or more of the following signs, you may have a chimney leak:
Check all that apply and contact your chimney specialist right away.
The constant exposure to changing weather conditions, including strong storms, lightning, snow, and ice, can damage the masonry resulting in one or more chimney leaks. Some common areas to look for a leak are the chimney cap, chimney crown, flashing, and mortar joints.
The chimney cap is an accessory that covers the exposed flue at the top of the chimney. If the chimney cap is missing or damaged, water can leak into the fireplace when it rains. The moisture can accelerate the deterioration of the interior masonry walls, chimney liner, and firebox. It can also cause the damper to corrode and rust.
Another common source of a chimney leak is the cement crown. The chimney crown is the top of a masonry chimney. It has a sloped design to deflect water away from the chimney, but when it begins to crack, water can enter the chimney system and damage its internal components.
The chimney flashing covers the seam where the chimney and roofline meet. Severe weather, including wind, rain, snow, and ice, can damage the metal flashing. When the metal flashing is damaged, rusting, or warping, water can seep between the gaps and leak inside the chimney. It can cause extensive damage to the interior masonry walls. It can also damage the attic and roof.
Brick and mortar are porous materials that absorb moisture. It can make the clay material inside the bricks soft and spongy. When the absorbed moisture freezes and thaws throughout the winter months, it causes cracks in the bricks and gaps in the mortar joints to expand continually. As these masonry cracks widen, they become additional entry points for water leaks. If the masonry damage is not repaired quickly, the brick and mortar will continue to deteriorate, eventually leading to a chimney collapse.
A waterproof chimney sealant is a protective coating that can be applied to protect the masonry from water intrusion. To avoid further brick and mortar damage, only use a vapor-permeable waterproof sealant on the chimney. It repels water while allowing the masonry to “breathe” without locking in moisture or harmful gases. Damaged bricks and mortar need to be repaired before waterproofing the chimney. The waterproof sealant will need to be re-applied every 5 to 7 years to maintain maximum effectiveness.