What happens if my house tests positive for mold?


Editorial team Published on

If your house tests positive for mold, you must find and stop the moisture source, clean or remove contaminated materials, and protect your health.

Immediate Steps to Take

  • Find and fix the water source: Mold cannot grow without moisture. Repair plumbing leaks, fix roof or window leaks, or lower indoor humidity below 50% to 60% immediately. Cleaning the mold without fixing the leak means it will grow back.
  • Assess the size of the problem:
    • If the affected area is small (under 10 square feet), you can usually clean it yourself.
    • If the affected area is large (over 10 square feet) or involves hazardous types like black mold (Stachybotrys chartarum), you should hire a professional remediation contractor.
  • Isolate and protect yourself:
    • Close doors and seal off the work area with plastic sheeting if you are cleaning a small patch.
    • Wear proper personal protective equipment (PPE), including an N-95 respirator, gloves, and eye protection.

Cleaning and Removal

  • Hard surfaces: Scrub hard surfaces (like tile, glass, or sealed wood) with water and detergent or soap, then dry completely. (The California Department of Public Health and the U.S. EPA note that bleach is usually unnecessary or not recommended).
  • Porous and absorbent materials: Throw away porous items—such as ceiling tiles, insulation, carpet, or drywall—if they are deeply molded or have been wet for more than 24 to 48 hours. Mold roots itself into the spaces of these materials and cannot be fully washed out.

Health Risks

  • Allergic reactions: Inhaling mold spores can trigger sneezing, runny nose, red eyes, skin rashes, and sore throats.
  • Asthma and breathing issues: Dampness and mold can cause asthma attacks or worsen wheezing and coughing.
  • Vulnerable groups: Children, the elderly, people with chronic respiratory conditions, and individuals with weakened immune systems face higher risks of severe reactions or infections. Consult a healthcare provider if you experience persistent symptoms.

Real Estate and Disclosure Rules

  • Property disclosure: If you plan to sell your house, many states and local laws require you to disclose past mold problems, water damage, or professional remediation work to prospective buyers, along with related documentation.