Whether it's the slimy black spots on your shower curtain, the fuzzy white patches on your basement floor, or the slick orange film that forms on your kitchen drain, household mold is more than unsightly. In some cases, mold in your home can make you sick, especially if you have allergies or asthma.
Mold Reactions: Who's at Risk?
For people sensitive to mold, inhaling or touching mold spores can cause allergic reactions, including sneezing, runny nose, red eyes, and skin rash. People with serious mold allergies may have more severe reactions, including shortness of breath. In people with asthma who are allergic to mold, breathing in spores can also cause asthma attacks.
In addition to people with allergies and asthma, others who may be more sensitive to the effects of mold include:
- Infants and children
- The elderly
- People whose immune systems are compromised due to HIV infection, cancer, liver disease, or chemotherapy
- People with chronic lung disease
What Is Mold?
Mold is a type of fungus that consists of small organisms found almost everywhere. They can be black, white, orange, green, or purple. Outdoors, molds play an important role in nature, breaking down dead leaves, plants, and trees. Molds thrive on moisture and reproduce by means of tiny, lightweight spores that travel through the air. You’re exposed to mold every day.
In small amounts, mold spores are usually harmless, but when they land on a damp spot in your home, they can start to grow. When mold is growing on a surface, spores can be released into the air where they can be easily inhaled. If you're sensitive to mold and inhale a large number of spores, you could experience health problems.
Where Do Molds Grow?
Your walls, floors, appliances, carpet, or furniture – they can all provide the food mold needs to grow. But the thing all molds need most is moisture, so you're most likely to see mold in damp places such as bathrooms, kitchens, laundry rooms, basements, and crawl spaces.
Top Tips for Controlling Mold
It's impossible to get rid of all mold and mold spores in your home, but because mold spores can't grow without moisture, reducing moisture in your home is the best way to prevent or eliminate mold growth. If there is already mold growing in your home, it's important to clean up the mold and fix the problem causing dampness. If you clean up the mold but don't fix the problem, the mold will most likely return.
Following is some advice for reducing moisture throughout the home with specific tips for the areas most prone to dampness and mold growth:
Around the house:
- Use dehumidifiers and air conditioners, especially in hot, humid climates, to reduce moisture in the air.
- Keep indoor humidity below 60% if possible. You can measure relative humidity with a hygrometer, an inexpensive instrument available at many hardware stores.
- Keep air conditioning drip pans clean. Make sure drain lines are free of obstructions and flow properly.
- Keep the house warm in cool weather. As the temperature goes down, the air is less able to hold moisture and it condenses on cold surfaces, which can encourage mold growth.
- Add insulation to cold surfaces, such as exterior walls, floors, and windows to reduce condensation.
- Dry wet areas within 24 to 48 hours to prevent mold growth.
- Fix leaks and seepage. The ground should slope away from your house. If water is entering the house from the outside, your options range from simple landscaping to extensive excavation and waterproofing.
- Have a heating and cooling contractor check your heating and cooling system to make sure it's sized and operating properly to remove humidity. If your system is too big or the airflow is incorrect, your air conditioner will not remove humidity like it should. Also, ask the contractor to check your duct system for air leaks, and proper size and air flow to each room.
- Open doors between rooms to increase circulation, which carries heat to cold surfaces. Increase air circulation by using fans and by moving furniture from wall corners.
In the kitchen:
- Use exhaust fans to move moisture outside (not into the attic) whenever you are cooking, washing dishes, or cleaning.
- Turn off certain appliances if you notice moisture on windows and other surfaces.
- Check for leaks around the kitchen sink, refrigerator ice makers, and other sources of water. Repair if necessary.
- Empty and clean refrigerator drip pans if necessary.
In basements and crawl spaces:
- Put a plastic cover over dirt in crawl spaces to prevent moisture from coming in from the ground. If there is standing water or the soil is wet, dry it out with fans before covering the floor.
- Be sure crawl spaces are well ventilated by using fans and having vents installed in outside walls if necessary.
- Consider painting concrete floors and using area rugs instead of wall-to-wall carpet in basements. If you plan to install carpet over a concrete floor, it may be necessary to use a vapor barrier (plastic sheeting) over the concrete and cover that with sub-flooring (insulation covered with plywood) to prevent a moisture problem.
- Have your basement floor checked for leaks and have them repaired if necessary. Water can enter your home by leaking or by seeping through basement floors or walls.
- Make sure gutters are working properly and that outdoor landscaping causes water to run away from -- not toward -- the house.
- Do not finish basement walls with insulation and wall board unless your basement is very dry.
In the laundry room:
- Vent your clothes dryer to the outside.
- Make sure the vent is clear of obstructions, such as lint, and that there are no holes that leak air. If the vent duct is damaged, replace it with a metal duct. Have the duct cleaned at least once a year.
- Avoid leaving damp clothes in the laundry basket or dryer. Wash and dry them promptly.
- Use exhaust fans to remove moisture to the outside (not into the attic).
- Use area rugs, which can be taken up and washed often instead of wall-to-wall carpeting.
- Check for leaks around basins and tubs and have them repaired if necessary.
- Open a window when showering.
- Avoid leaving damp towels on the floor or in the laundry hamper.