How Winter Weather Can Damage Your Chimney System

Frigid temperatures are the reason we love to sit near our fireplaces in the glow of crackling fires. But did you know that harsh winter weather can damage your chimney system, as well? The Chimney Safety Institute of America (CSIA) sheds light on what occurs. The deterioration of chimney masonry and mortar joints is accelerated in below-freezing temps, especially when moisture has infiltrated the bricks. A leaky chimney is just one of the potential unwanted outcomes.

Chimneys are Vulnerable to Moisture

Moisture is the number one cause of chimney damage and deterioration. The reason chimneys are so vulnerable is that bricks are prone to absorb moisture. Although chimneys are built to keep moisture out, each component contributing to that purpose is also prone to deteriorate. Examples follow:

• The chimney crown prevents water from penetrating the chimney system between the chimney exterior and the flue liner. The material used to build chimney crowns tends to crack and deteriorate, however, which renders it ineffective in keeping moisture out until repairs are made.
• Chimney flashing is supposed to create a waterproof seal between the chimney and the roof. Flashing tends to fail, however, whether due to poor installation or brutal winds. Rooftops have been known to rot and the bricks behind the chimney flashing are often destroyed by moisture due to flashing damage.

Why Freezing Weather Wreaks Havoc on Chimneys

When moisture infiltration has occurred in the chimney, the freezing and thawing cycles of winter destroy each affected brick. What happens is that the moisture expands and contracts as it freezes and thaws. The movement breaks down the bricks. They eventually flatten, which creates the need for chimney masonry repair, a partial chimney masonry rebuild, or a complete rebuild. If needed repairs are not made, the chimney will eventually start leaning and could collapse.

How Can Waterproofing Help?

To keep moisture out of chimneys, ongoing vigilance is required. Routine monitoring of chimney components is essential, which is best achieved by scheduling annual chimney inspections. For an extra line of defense against destruction caused by rain, sleet, snow, and other types of moisture, schedule chimney waterproofing. Chimney professionals apply sealants that are 100% vapor permeable. As a  preventative measure, waterproofing helps to reduce y future chimney repair costs.

Waterproofing is not an option if the chimney system already contains moisture. The chimney system must be repaired and free of moisture and deterioration before a layer of waterproofing is applied.

Signs of a Chimney Leak or Water Damage

It is seldom immediately obvious when moisture has infiltrated a chimney system. The following are some of the signs that icy winter weather has damaged your chimney:

• The masonry is stained.
• Dripping sounds are heard from the fireplace.
• The ceiling and/or walls near the chimney have water stains.
• Metal components of the fireplace are rusted.
• The fireplace emits musty odors due to mold or mildew.

Are you concerned that winter weather has damaged your chimney system? Our CSIA-certified chimney sweeps are ready to help. Call Felgemacher Masonry + Chimney in Buffalo at (716) 907-4914 or in Rochester at (585) 308-4914 to schedule a chimney inspection today. You can also reach us using
our online form.