How Summer Storms Can Affect Your Chimney

As homeowners throughout Tennessee and Alabama enjoy the warm summer weather, the higher temperatures and humidity also bring summer storms which can have a devastating effect on your chimney. The strong winds, heavy rain, and lightning often associated with summer storms can damage the chimney masonry structure.

In addition to frequent downpours, the Northern Alabama and Southern Tennessee Valley can also experience a microburst, a sudden downburst of wind and rain that falls to the ground within seconds at up to 100 mph. Although your chimney may appear to be unscathed after a storm, it could have sustained cracks and other damage. Water can seep through tiny cracks that can cause widespread damage to the chimney system.

Chimney Cap Damage

Make sure you have a sturdy chimney cap and that it is securely attached to the chimney. The chimney cap helps to keep rainwater out of the flue and fireplace. It can also prevent sudden downdrafts that can blow soot, dust, and debris out of the fireplace and into your living space. However, during a summer storm, the chimney cap can sustain damage, become loose, and eventually separate from the chimney leaving your fireplace vulnerable to small animals, pests, and mold.

Chimney Crown Cracks

The cement chimney crown tops the masonry structure to deflect precipitation away from the chimney. Cracks can develop on the cement surface due to age, settling, and violent storms. When rainwater leaks into the flue through cracks in the chimney crown, it can damage the interior masonry walls, flue liner, and other internal components. If left unrepaired, the damage will worsen, and the cement surface will ultimately begin to crumble, requiring the chimney crown to be rebuilt.

Masonry Damage

Here in the Tennessee Valley, we experience many seasonal weather changes. These changing weather conditions affect your chimney. The frequent freeze-thaw cycles we experience during the winter, for example, cause tiny cracks to develop in bricks and mortar. These cracks continue to expand with each freeze-thaw process, eventually causing the bricks to spall or chip, flake, and crumble, leaving gaps in the mortar joints. During the summer, the high humidity and frequent storms can exacerbate any existing masonry damage leading to water leaks that can weaken the chimney’s structural integrity.

Flashing Damage

The flashing is the sheet metal that seals the seam between the chimney and roof to prevent water leaks through the gap. Several seasons of extreme weather conditions, including hail and hot summer temperatures, can weaken the flashing material causing it to warp or corrode. Flashing damage requires immediate repair or replacement to prevent water damage to the attic, roof, and masonry.

Protecting Your Chimney from Summer Storms

An annual chimney inspection is the best way to protect your chimney from summer storms. Our Certified Chimney Sweep® will visually examine the entire chimney system, including vents and attached heating appliances like your fireplace or heating stove. A chimney inspection can often spot minor cracks and other damages before becoming more severely damaged in a strong storm. In addition, making timely masonry repairs and waterproofing your chimney will provide year-round moisture protection prolonging the lifespan of your chimney.