Home Tap to Call Now Visit Blog

TN / 931-967-3595AL / 256-285-4895

Common Causes of Chimney Moisture Damage

Years of exposure to rain, snow, temperature swings, and other inclement weather that we experience in the Southern and Middle Tennessee Valley can accelerate the deterioration of your chimney and cause moisture damage. Sometimes chimney leaks are apparent, like observing a puddle of water in the fireplace or stains on the ceiling. However, other leaks like cracks in the chimney masonry or crown are not always visible until more extensive damage occurs. To avoid extensive chimney repairs, keep an eye out for these four common causes of chimney moisture damage.

chimney flashing replacement, winchester tnWorn Flashing

Worn or damaged flashing is one of the most common causes of chimney moisture damage. The metal flashing creates an airtight seal along the seam between the chimney and roof to prevent water leaks that lead to moisture damage. However, normal wear and tear, environmental conditions, and low-grade materials can eventually cause the flashing to warp, corrode, or rust. One of the telltale signs of a flashing issue is water stains on the walls or ceiling around the fireplace, which is why flashing damage is often mistaken for roof leaks. Since improper chimney flashing installation can lead to premature failure, flashing repairs should only be accomplished by a licensed and certified chimney professional like an
A-1 Chimney Specialist.

Masonry Cracks

Another common cause of moisture damage is masonry cracks. The continued exposure to winter weather conditions such as rain, snow, and ice, can cause bricks and mortar to crack, chip, and crumble. As the condition worsens, the decaying mortar can cause bricks to loosen and separate from the roof, exposing gaps in the mortar joints. Masonry cracks are especially problematic because they can create multiple entry points where water can leak inside the chimney and cause extensive damage to the interior masonry walls, chimney liner, and other chimney sections. In addition to increasing the risk of fire and exposure to harmful fumes, significant chimney moisture damage can severely weaken its structural integrity, leading to a complete or partial collapse.

Missing or Broken Chimney Cap

The chimney cap is the first line of defense for protecting the chimney against moisture damage. It also helps protect the chimney crown too. However, its location at the top of the chimney makes it prone to weather-related damage that can cause the cap to crack or separate from the chimney allowing precipitation to leak inside the flue that can cause damage to the masonry chimney liner and damper. Moisture in the chimney can also promote the growth of mold, fungus, and bacteria that can cause foul odors, especially during the wetter and more humid months. It can also be unhealthy for persons with allergies and chronic respiratory conditions that can be exasperated by these growing allergens.

chimney crown repair, new hope alabamaChimney Crown Cracks

The cement chimney crown tops the entire masonry structure with a slope design to deflect rainwater away from the chimney. It may also have a drip edge which also helps to prevent moisture intrusion. However, normal wear and tear, house settling, and severe weather conditions can cause cracks in the cement surface, significantly if the chimney cap is damaged or missing. When water leaks through the cracks, it will cause the cracks to widen, further increasing damage to the crown and can also cause extensive moisture damage to the chimney, liner, and other components.

Signs Your Chimney May Be Leaking

  • Cracks in the bricks and mortar
  • Hearing sounds of water dripping in the chimney
  • Water in the firebox
  • Condensation on the interior masonry walls or liner
  • Water stains on the walls or ceilings around the fireplace
  • Musty odors

Preventing Chimney Moisture Damage

Annual chimney inspections are the best way to ensure your chimney and fireplace are in safe operating condition and prevent chimney moisture intrusion that can lead to extensive damage, repairs, and replacement. Contact A-1 Chimney Specialist to schedule an appointment today.