Water’s Effects on Chimneys

During the summer, chimneys are typically a forgotten feature on top of roof lines across the country. Unfortunately, the months between May and August see increased rainfall, which puts the structure on top of your roof at risk of developing dangerous, and oftentimes costly, damages. One of the major threats to chimneys and homes during the summer is the dreaded water leak.

Masonry chimneys are especially vulnerable to spring and summer rain showers. Brick, mortar, concrete, steel, cast iron and flue tile are all used to construct these chimneys, and almost all of  them can sustain serious damage from water penetration. Mortar that is exposed to rain can chip away, resulting in loose bricks and water leaks that can in turn cause interior damage in your  home.

 Effects of water penetration

Some examples of common problems that result from water damage in masonry chimneys include:

  • Rusted damper assemblies
  • Tilted or collapsed chimney structure
  • Water stains on ceilings or walls
  • Cracked flue liner
  • Chimney settlement
  • Chimney odors

Preventing water damage

Chimney caps, also known as rain covers, are an inexpensive solution to water penetration. Made from durable, corrosion-resistant materials, caps cover the flue opening to keep out rain, snow and any other substance that could potentially damage your chimney and fireplace.

The flashing  acts as a waterproof seal between the roof and the base of the chimney. Effective flashing systems will keep water from running off the chimney and through gaps in the roof.

Repairing deteriorated mortar joints and chimney crowns regularly will ensure that they remain in good condition. Mortar joints with gaps are more likely to let water in, where it can access the interior of your chimney and home. Chimney crowns should be built in a downward slope that hangs off the chimney by at least two inches so that water is directed away from the structure. They should also be made from durable cement-based mixes to withstand years of weather abuse.

Professional chimney sweeps offer waterproofing services to protect your chimney from the effects of rain and moisture. ChimneySaver and CrownSaver are two of the top products in the industry for sealing chimney masonry and crowns, while allowing the bricks and mortar to still breathe so that water vapors can escape. They will slow down the natural process of deterioration so that your chimney is in good condition for years to come.