What should I do if I have mold in my house?

Managing Mold in Your House

For mold-contaminated areas less than 10 ft², individuals can clean using commercial products, soap and water, or a bleach solution (1 cup bleach to 1 gallon water), while areas larger than 10 ft² require professional remediation. 1

Immediate Steps for Mold Remediation

Small Areas (Less than 10 ft²)

• Clean using one of the following:
  • Commercial mold removal products
  • Soap and water
  • Bleach solution (1 cup bleach to 1 gallon water) 2, 1
• When using bleach:
  • Never combine with ammonia or other household cleaners
  • Ensure good ventilation during use
  • Apply to hard, non-porous surfaces (tile, countertops, metal, plastic, glass, concrete) 2

Large Areas (More than 10 ft²)

• Hire professional remediation services, especially if: 2, 1
  • Mold growth exceeds 10 ft²
  • HVAC system is involved
  • Water damage was caused by sewage or flooding
  • You have extensive water damage

Prevention Strategies

• Control moisture - the key to preventing mold growth:

  • Maintain indoor humidity below 50% 1
  • Use dehumidifiers in damp areas
  • Promptly repair water leaks
  • Improve ventilation in bathrooms and kitchens 1

• Regular maintenance:

  • Change filters on central forced-air systems according to manufacturer recommendations 2
  • Consider upgrading to medium-efficiency filters (20%-50% efficiency at removing particles between 0.3 and 10μm) 2
  • Regularly clean and maintain HVAC systems and air conditioners 1

Special Considerations

Porous vs. Non-porous Materials

• Non-porous materials (tile, metal, glass) can typically be cleaned effectively
• Porous materials (carpet, drywall, wood) may need to be discarded if extensively damaged, as mold can be difficult to remove completely 2

Humidifiers and Air Quality

• Use humidifiers cautiously as they can promote mold growth if not properly maintained
• Clean humidifiers frequently according to manufacturer instructions 2
• Consider that increased humidity can contribute to dust mite populations and mold growth 2

Air Cleaners

• HEPA filters and electrostatic filters/precipitators can help remove mold spores from air 2
• Avoid "air purifiers" that emit ozone, as these can produce harmful concentrations of ozone indoors 2

Health Implications

• Mold exposure can cause allergic reactions, particularly in sensitive individuals 3, 4
• Approximately 5% of individuals may experience allergic airway symptoms from molds over their lifetime 3
• The most important intervention for mold-related symptoms is removal from the exposure source 1

When to Seek Professional Help

• For remediation:

  • Mold covers more than 10 ft²
  • Water damage is extensive
  • HVAC system is involved
  • Damage was caused by sewage or flooding 2, 1

• For health concerns:

  • Persistent respiratory symptoms
  • Individuals with pre-existing allergies, asthma, or compromised immune systems 1

Common Pitfalls to Avoid

• Delay in addressing water damage - remediation should be performed promptly 2
• Improper cleaning techniques - using bleach on porous materials may not be effective 2
• Ignoring hidden mold - mold can grow behind walls and under carpets 1
• Overreaction to mold presence - while mold should be addressed, normal levels of mold spores are present in all indoor environments and cannot be completely eliminated 3