7 Common Causes of Summer Mold in Your Home

1. High Humidity Levels

Warm summer air has more moisture. Without good ventilation or dehumidification, indoor humidity can go above 60%. This creates a perfect environment for mold.

Prevention Tips:

• Use a dehumidifier in moisture-prone rooms (basements, laundry rooms).

• Keep indoor humidity levels between 30%–50%.

• Run your HVAC system regularly to circulate and condition the air.

2. Poor Ventilation

Rooms that lack proper airflow, such as bathrooms, attics, and closets, often trap moisture and heat.

Prevention Tips:

• Install exhaust fans in bathrooms and kitchens.

• Open windows when weather permits to increase cross-ventilation.

• Use ceiling fans or box fans to improve air circulation.

3. Leaky Windows and Doors

Even a small leak around a window or door frame can lead to excess moisture, especially after summer rainstorms.

Prevention Tips:

• Inspect windows and doors for cracks, gaps, or deteriorating seals.

• Apply weather-stripping or caulk any leaks.

• Replace damaged or rotted wood trim immediately.

4. Flooding or Heavy Rain

Sudden summer downpours or localized flooding can lead to water intrusion in basements, crawlspaces, or ground-level floors.

Prevention Tips:

• Ensure your gutters and downspouts are clean and directing water away from your foundation.

• Install a sump pump with a battery backup in flood-prone basements.

• Grade your yard to slope water away from your home.

5. Damp Clothes or Towels

Leaving wet clothes or towels in hampers, on floors, or in piles creates a localized humidity pocket—perfect for mold.

Prevention Tips:

• Always hang towels to dry immediately after use.

• Avoid overloading laundry rooms or closets with damp items.

• Wash and dry clothes promptly, especially in humid conditions.

6. HVAC Condensation

Air conditioners work hard in the summer. If not managed well, condensation from coils or ducts can leak into walls or ceilings.

Prevention Tips:

• Schedule regular HVAC maintenance to check for leaks or clogs in the drain line.

• Insulate ducts to prevent sweating in humid conditions.

• Replace filters regularly for better airflow and moisture control.

7. Overwatering Houseplants

Too much water sitting in plant trays or soil can raise humidity and encourage mold in nearby surfaces.

Prevention Tips:

• Water plants only as needed and allow proper drainage.

• Avoid placing plants too close to walls or corners.

• Clean trays regularly to prevent mold buildup.

Signs of Mold in Your Home

• Musty or earthy odor

• Discolored patches on walls, ceilings, or floors

• Allergy-like symptoms (sneezing, coughing, itchy eyes)

• Visible mold spots, especially in corners or damp areas

When to Call a Professional Mold Remediation Company

If mold keeps coming back despite your efforts, or if you spot black mold, it’s time to bring in experts. A certified mold remediation company can:

• Inspect hidden mold in walls or air ducts

• Use moisture meters and infrared to detect water damage

• Perform safe, effective mold removal and prevention