What Are the Worst Types of Mold Found in Homes?

Stachybotrys chartarum, often called black mold, is one of the most concerning molds you can find. It appears as dark green or black patches, usually on drywall, wood, or paper after prolonged moisture. This mold is linked to respiratory problems, headaches, and allergic reactions, especially in children or those with asthma.

You often see it after a hidden leak or flood, where materials stayed wet for days. Because it grows deep into porous surfaces, simply wiping it away is not enough. If you notice a musty smell or dark spots, avoid touching it. Local water damage pros can identify the extent and remove affected materials safely.

• Dark green or black in color
• Grows on drywall, wood, or paper
• Needs constant moisture to thrive
• Can cause breathing issues or skin irritation
• Often hidden behind walls or under carpets

Aspergillus is a common mold that many homes have in small amounts, but it becomes dangerous when it grows out of control. It can appear as yellow, green, or brown patches on damp insulation, carpets, or food. For most people, it causes mild allergies, but for those with weakened immune systems, it can lead to serious lung infections.

Indoor Aspergillus often comes from dust and moisture, so you may find it in HVAC systems or after a pipe leak. You cannot always see it, but a musty smell or increased allergy symptoms are clues. If you suspect it, keep the area dry and seek professional help for testing and cleanup.

If you find mold, your first step is to limit your exposure. Wear gloves, goggles, and an N95 mask if you plan to clean small areas. Do not dry-brush or vacuum mold, as that sends spores into the air. Instead, use a damp cloth and a mild detergent for non-porous surfaces, and throw away anything that cannot be cleaned.

For mold that covers more than a few square feet, or if it is in drywall, insulation, or other porous materials, call the pros. They have the equipment and training to remove mold safely and address the moisture source, such as a leak or flooding. Also, consider checking with your insurance company, as some policies cover mold damage. Policies vary, and your insurer decides what is covered.