More than 50% of homes in America have a mold problem, according to This Old House. While it’s common for bathrooms, kitchens and bedrooms to develop a mold problem, homeowners rarely consider looking for it in their chimney and fireplace. However, moldy chimneys and fireplaces are more common than you think, and could be the reason for the musty smell in your home, so it’s crucial you get rid of it once and for all.

Getting to the root cause

There are several different parts of your chimney that could be to blame for mold growth. As a general rule, it could be one of four things causing the mold:

• A lack of ventilation
• A damaged chimney crown
• The brick and mortar
• A damaged chimney cap

Mold occurs in damp and cold places, so when there’s poor ventilation, any damp that does get in has nowhere to go and causes mold. If the chimney crown or chimney cap fail, this can add to the amount of moisture that gets into your chimney, thus worsening the problem. Meanwhile failing to waterproof the brick and mortar that sits within the chimney allows an increasing amount of water to build up, and will quickly lead to mold growth.

Clean up operation

When you suspect that mold has taken over your chimney and fireplace, you should cease using it and arrange for it to be cleaned. If there’s just a small amount of mold visible then you can clean it with an anti-fungal spray and a scrubbing brush. However, it’s best to call in an expert mold cleaning service, as with a chimney, you can never be sure how far the mold has spread or the true extent of the problem. To tackle mold fully, a mold remediation company will thoroughly inspect, assess, and test your chimney and fireplace. From there, they’ll treat the mold with an anti-microbial system, before checking that the mold hasn’t spread further around your home.

Solving the problem

Once the mold from your chimney and fireplace have been professionally removed, you’ll find that your home will instantly smell better. To ensure that things stay this way, you’ll need to tackle the root cause of the problem. This means replacing any faulty parts of your chimney, installing adequate ventilation, and damp-sealing all the bricks and mortar in and around the chimney. It’s also a wise idea to have your chimney professionally inspected annually. An inspection will identify any damp problems early on so that you can take action to remedy them before the mold returns and ruins the inside of the chimney, emitting that annoying musty odor.

Just like any part of your home, your chimney and fireplace are susceptible to damp and mold problems. But there’s no need to worry if you do suspect that mold is invading your chimney, as it’s simple enough to remove it. And, so long as you take preventative action to keep it at bay for good, you won’t have to deal with again.

We spend, on average, roughly 90% of our time indoors, where concentrations of pollutants can be up to five times higher than they are outdoors. For those of us burning wood indoors, this can be particularly concerning, but the good news is that by using a wood stove rather than an open fireplace, you’re already breathing in far fewer pollutants, and many of the steps you take to keep your stove eco-friendly will also help minimize the level of pollutants in your home. That said, it’s important to be aware of the effects of wood smoke and what you can do to improve your indoor air quality when you use a wood stove.

The Effects Of Burning Wood In The Home

When we breathe in wood smoke, we inhale pollutants and small particles, which can cause irritation to the lungs and eyes, and exacerbate breathing difficulties like bronchitis and asthma. Heavy exposure in the long term can lead to heart difficulties and reduced lung function, particularly in infants and older adults. 

There are a few steps you can take to reduce the amount of toxins you breathe in from wood smoke. Improving filtration and ventilation is key, as this exchanges stale air for fresh air. Air conditioning systems filter indoor air to remove airborne particles, and some also act as air purifiers - make sure you understand the parts and functions of your unit, and install air purifiers if yours doesn’t have one. Clean HEPA filters regularly, and monitor the air quality with an indoor air monitor, which will alert you if there’s a reduction of the quality of the air in your home.  

Keep Your Wood Stove Clean And Well-Maintained

Ensure that your wood stove is certified by the EPA - modern stoves are cleaner and more efficient, and this certification is required, but if you’re using a very old stove, it may be time to upgrade. Modern stoves burn less wood than older stoves, and reduce the amount of wood smoke emitted.

Ensure that any air leaks are sealed and insulated, and have your stove serviced regularly. The chimney, too, should be swept once a year to clear out creosote and pollutants. As well as keeping your air quality at its best, this will ensure the safety of your stove.

Using Your Stove For Optimum Air Quality

To keep pollutants to a minimum, burn only dry, natural wood. Damp wood doesn’t burn as easily, and will produce much more smoke, as well as generating less heat. Stack split wood off the ground for six months to a year to season it, keeping it covered with plenty of room for air flow. Cracking at the ends of the logs will show you when the wood is dry. Dry wood should also make a hollow sound when two logs are knocked against each other. You can use a moisture meter to check that the wood is dry enough - moisture content should have dropped to 15-20% before burning. 

When you’re building your fire, stack larger logs at the bottom, followed by smaller logs topped with sticks or wood chips. When you’re lighting the stove, light the top of the pile. Keep the fire hot, as this produces a cleaner fire with little visible smoke. 

Because a wood stove keeps the fire contained, it causes far less problems for indoor air quality than an open fireplace. However, in order to keep the air quality of your home as clean as possible, it’s important to keep your stove well maintained and pay attention to the moisture content of the wood you’re burning. Doing this will also reduce the stove’s environmental impact, and keep it burning at its most efficient level.