Many homeowners have their own horror stories of finding mold lurking in dark, dank basements, hiding beneath floors after a flood, or growing around leaky windows or doorframes. But did you know that mold can grow in your chimney, too?
When left without regular maintenance, fireplaces and chimneys are the perfect breeding grounds for toxic mold. Left unchecked, mold in the chimney can cause seriously unpleasant odors – and have a significant negative impact on the air quality in a home. The following guide can help homeowners understand what causes mold growth in chimneys, the signs mold is present in a chimney system, and how to prevent it from occurring.
What causes mold to grow in fireplaces and chimneys?
There are three main factors that cause mold growth in fireplaces and chimneys: poor ventilation, lack of natural light, and naturally cool temperatures. Fireplaces and chimneys are ideal breeding grounds for mold minus one significant detail – water. Without moisture, there is no mold growth. Unfortunately, many homeowners experiencing an ongoing or long-term chimney leak also face mold growth.
Water can enter a chimney system in a variety of ways. Some of the most common causes of water entry are:
- Damaged chimney crown. The chimney crown is the masonry slab that surrounds the top of the flue, sealing off and protecting the structure. Chimney crowns often bear the brunt of the exposure to the elements; they are particularly vulnerable if they are not built slightly angled, which can lead to standing water on the chimney crown. Just one small crack can let in enough water to fuel mold growth.
- Cracked masonry. Like the chimney crown, the bricks and mortar of the chimney are susceptible to water damage. Small cracks or holes in the masonry can cause water to seep through.
- Damaged chimney cap. The chimney cap is the metal hood that covers the top of the flue. When damaged – or missing entirely – water from rain and snow can drop directly into the chimney and fireplace. In addition to mold growth, this type of leak can cause significant damage to other delicate chimney components.
Dangers of mold in the chimney
Mold, no matter where it is in the house, is a health hazard to residents. There are a number of ways that mold can cause problems within the home.
1. Health and breathing issues. While mold growth may go unnoticed for long periods of time, the release of mold spores can lead to health problems – particularly in children, the elderly, or those with respiratory illnesses such as asthma.
Reactions to mold spores often begin as cold-like symptoms, which can make it difficult to differentiate from a regular illness. Symptoms such as coughing, sneezing, sore throat, wheezing, or headache are common; because mold in the chimney is often difficult to identify, these cold-like symptoms may not be associated with mold growth. If the mold is not correctly removed, symptoms can be more severe. In extreme cases, mold spores have been known to cause pneumonia, effecting those with allergies or asthma in particular.
2. Water damage to the fireplace system. Fireplaces are built to withstand heat – not moisture. When delicate interior fireplace and chimney components are exposed to water they can become weakened; this can damage the structural integrity of the chimney. Rusted dampers, cracked flue liners, or warped masonry joints are common issues that are seen with chimney leaks.
3. Unpleasant odors. While odors themselves are not a risk to the health or safety of your family, they can make a home very unpleasant. Odors caused by mold are very noticeable and difficult to mask. Without removing the source of the smell, these odors will continue to worsen. Unfortunately, if left too long with removal, mold odors can linger even after the mold has been removed.
Removing fireplace mold
If you think you have mold in your fireplace system, a chimney inspection is the most effective way to diagnose the problem. Because there are a wide variety of health risks associated with mold spores, it is extremely important that homeowners not attempt to remove mold themselves. Instead, trust a trained chimney technician to diagnose and safely and completely remove mold from the chimney system.
While removing mold can improve the air quality of a home, it does not solve the underlying issue: what caused the mold growth in the first place? If moisture continues to enter the chimney system, mold will continue to grow back. As part of the chimney inspection, your chimney sweep can help identify – and give recommendations to repair – the source of water entry. Once water can no longer enter the fireplace system, mold should stop growing.
Preventing fireplace mold
The most effective way to prevent fireplace mold is by preventing chimney leaks. While chimneys have the ideal conditions for mold growth, only the presence of moisture allows mold to grow; if water is not allowed into the fireplace system, there will be no mold growth.
Annual chimney sweepings and inspections can help prevent chimney leaks from occurring by spotting small problems before they turn into major issues. This type of annual maintenance includes inspecting portions of the chimney, such as the chimney cap, for signs of damage or deterioration.
Contact us today to protect your home against mold!
Mold growth puts the health of everyone in your home at risk. At Coopertown Services, our chimney technicians have the knowledge and skill to safely remove mold from your chimney – and keep it from coming back. Contact us today for more information on protecting your fireplace system against mold.