Oregon State University Extension Service

Mold control: Home inspection checklist

Indications of excess moisture in the home

  • Moisture meter indicates level above 50% relative humidity
  • Musty smell
  • Mold on surfaces (window sill, in closets, behind furniture)
  • Condensation on windows, toilets and exposed pipes
  • Water stains on window sills, ceilings, walls
  • Moisture under plastic in basement
  • Airtight construction allows odors to linger
  • Damp bottoms on cardboard boxes sitting on the floor

Controlling sources of indoor moisture

Lifestyle of residents

  • Limit number of occupants in living space
  • Hang laundry outside to dry
  • Leave wet shoes, coats and umbrellas outside to dry
  • Keep home and clothes clean
  • Cover aquariums
  • Limit houseplants
  • Keep pets and their food and water dishes clean and dry


  • Vent clothes dryer to the outside
  • Empty refrigerator drip pan regularly
  • Empty dehumidifier tank regularly
  • Maintain air conditioner filter, coils, line
  • Properly vent combustion heating appliances to the outside
  • Store firewood outside
  • Use humidifiers rarely
  • Maintain moderate indoor temperatures during the heating season

Identify and repair leaks

  • Plumbing, including pipes to refrigerator, water heater, faucets and drains under cupboards and laundry spigots
  • Roof, including vents and skylights
  • Windows, doors
  • Foundation vents

Adequate air circulation throughout the home

  • Keep furniture away from walls
  • Open drapes or curtains
  • Leave interior doors open
  • Open heating/cooling vents
  • Maintain heating, ventilating and air conditioning system
  • Keep low wattage bulb on in closets or small enclosed areas

Eliminating potential sources of water infiltration

  • Cover exposed soil in crawlspace with vapor barrier
  • The concrete foundation has adequate exterior protection from water
  • Drainage directs water away from or around the house
  • No water pools near the foundation of the house
  • Keep rain gutters free of debris and in good repair
  • Downspouts carry water away from house
  • Siding is sealed along bottom edges
  • Don’t allow water from sprinklers to hit the house
  • Trim back plants and shrubs to allow airflow around exterior of the home
  • Maintain and keep exterior of house free from mold

Removing moisture from home

  • Fans for spot ventilation
    • Placed near moisture source in the kitchen, bathroom and laundry rooms
    • Vented to the outside
    • Check for effectiveness
    • Leave on until all moisture is eliminated. (Install timers or controls with moisture meters built-in)
  • Roof vents to allow ventilation in attic space
  • Open vents in foundation to allow airflow
  • Control condensation on cool surfaces inside the home including
    • Single pane windows
    • Uninsulated walls
    • Unfinished basements
    • Uninsulated or metal doors
  • Install and regularly use a dehumidifier
  • Carefully clean and dry any signs of mold

Share these tips by downloading the Stamp out Mold in your Home handout (https://oregonstate.box.com/s/19wqvvhawceb7l4746rdmrlhusa8g8ms).

Source URL: https://extension.oregonstate.edu/families-health/healthy-homes/mold-control-home-inspection-checklist