What to Do If You Think You Have Mold in Your Fireplace or Chimney

Mold are fungi spores that can grow anywhere in your home, including your fireplace and chimney during warm, damp and humid conditions. The tiny spores are invisible to the naked eye but can make their way into the fireplace or chimney through tiny cracks or crevices – sometimes even hitching a ride on leaves that fall through the flue. Once inside they can reproduce very quickly even without the presence of moisture.

As the mold continues to grow and spread in the chimney or fireplace you may notice black spots or fuzzy spores clumped together. There may also be a strong pungent, musty or ammonia-like odor, especially after rainfall. Mold can be dangerous to some individuals and its presence can cause skin and eye irritation and wheezing, for example. However, even healthy individuals have had respiratory issues after coming into contact with mold, according to the Institute of Medicine (IOM).

Close the Fireplace Door

If you think you have mold in your fireplace or chimney, tightly close the fireplace door to prevent the fungi spores from spreading in your home.  Keep small children, pets and those with allergies away from the fireplace. Do not touch or breathe in the mold. The tiny spores can enter your lungs and may lead to respiratory problems.

Contact a Chimney Sweep

Contact a certified chimney sweep immediately and let them know you think you may have discovered mold in your fireplace or chimney. Chimney sweeps have specialized tools and equipment that will confirm whether or not mold is present. If your chimney or fireplace tests positive for mold, the chimney sweep will safely remove it. Your chimney and fireplace will also be inspected and thoroughly cleaned.

Make Chimney or Fireplace Repairs

Also, install a chimney cap to help keep, water leaves and other debris from blowing inside the flue. And ensure your damper is working properly and forms a tight seal when closed. Always close the damper when the fireplace is not in use. Repair or replace a damaged damper.

Preventing Mold Growth

The U.S. Environmental Protection Agency (EPA) advises that moisture control is the key to preventing mold growth. It is recommended that you dry any wet areas in the chimney or fireplace within 1 to 2 days. Maintain your indoor humidity between 30 percent and 50 percent, if possible, to help prevent condensation. Ensure water does not collect in the firebox. Apply a waterproof sealant to prevent water and mold spores from penetrating through the masonry. Ensure your chimney is clean and safe for use with an annual chimney cleaning and inspection.