Mold and Your Home: What You Need to Know

What are molds and where do they grow?

Molds, like most fungi, break down plant and animal matter in the environment. They can grow almost anywhere there is moisture and organic material such as in soil, on foods and plants, and in people's homes. To reproduce, molds release spores, which can spread through air, water, or on animals.

View sources of mold in your home.

What should I do to prevent mold growth in my home?

The key to preventing mold growth is to identify and control moisture and water problems. Mold spores are everywhere, including your home, and they can grow on any surface that has sufficient moisture.

Common sources of moisture are:

  • Roof leaks
  • Indoor plumbing leaks
  • Outdoor drainage problems
  • Damp basements and crawl spaces
  • Steam from the bathroom or kitchen
  • Condensation on cool surfaces
  • Humidifiers
  • Wet clothes drying inside the home
  • A clothes dryer venting indoors
  • Poor or improper ventilation of heating and cooking appliances

How do I know if I have a mold problem?

You can usually see or smell a mold problem. Mold can appear as slightly fuzzy, discolored, or slimy patches that increase in size as they grow. Most molds produce musty odors that are the first indication of a problem. Mold can grow anywhere there is adequate moisture or a water problem. The best way to find mold is to look for signs of mold growth, water staining, warping, or to follow your nose to the source of the odor. It may be necessary to look behind and underneath surfaces, such as carpets, wallpaper, cabinets, and walls. There are some areas of the home that are always susceptible to mold growth and should be part of routine cleaning to control mold growth. These are:

  • Bathrooms; especially shower stalls, bathroom tiles, and shower curtains
  • Window moldings
  • The seal on the refrigerator door
  • Surfaces on and around air conditioners

How do I get rid of mold in my home?


  1. The first step to mold cleanup is to control the moisture problem. The source of the water or dampness must be identified and corrected.
  2. Porous materials with extensive mold growth should be discarded (e.g., drywall, carpeting, paper, and ceiling tiles).
  3. All wet materials that can't be cleaned and dried thoroughly should be discarded.
  4. Hard surfaces that are not decayed (rotten) can be cleaned. Small areas can be cleaned with soap and water. A licensed contractor should do the work if it is a large (greater than 10 square feet) mold problem or if you are highly sensitive to mold. Rubber gloves and an N95 mask are recommended for jobs other than routine cleaning.
  5. In areas where it is impractical to eliminate the moisture source, diluted chlorine bleach (one cup of bleach in five gallons of water) can be used to keep mold growth under control. In areas that can be kept dry, bleach may not be necessary, as mold cannot grow in the absence of moisture. When using bleach or any cleaner, ensure that enough fresh air is available to prevent eye, nose, or throat irritation.
  6. Inspect the area for signs of moisture and new mold growth. These may indicate the need for further repairs or material removal. High moisture areas like bathrooms need extra attention to prevent excessive moisture and water problems from causing mold growth.

Do I need to test for mold or know what kind of mold is growing in my home?

No. Mold testing is not recommended, nor is it required by any regulatory agency. There is no state or federal standard for mold in homes. Mold sampling and testing can be more expensive than simply cleaning and repairing the water problems that allow mold to grow. Knowing the kinds of mold present does not change this advice. Molds can be found anywhere, and mold levels vary widely, depending upon location, weather, and time of day. If you see any mold growth, you should take steps to fix the water problem and remove and clean the mold as soon as possible.

Should I have my home inspected?

In most cases hiring a licensed mold assessment contractor is not necessary. Most people can identify and clean mold growth themselves. However, some people may choose to hire a NYS licensed mold assessor to help identify mold problems and their cause. They will often recommend a licensed mold remediation company to come in and clean the mold properly if needed. Check that a company is licensed by the NYS Department of Labor to perform mold remediation.

If you are a co-op or condominium owner, you may need to coordinate such services through the building’s management company or owners’ association for your building.

What if I am a renter?

As a tenant, you are expected to keep your dwelling clean and give attention to high moisture areas like bathrooms and kitchens. You should clean small amounts of mold or staining as described above. If mold growth is persistent or you identify any water leaks or damage, you should ask your landlord/superintendent to inspect and repair the problem(s). If the landlord is not taking care of the problem, you can ask your local building department or code enforcement official to inspect your home for water damage or leaks.

The Residential Tenants’ Rights Guide can explain many of the laws that can help you and provide resources where you can find more information about landlord and tenant issues, like mold.

Can mold make my family sick?

Exposure to mold can cause health effects in some people. Mold spores are always found in the air we breathe, but extensive mold contamination may cause health problems. Breathing mold can cause allergic and respiratory symptoms.

It is hard to say how much mold will cause health problems as some people are more sensitive to mold than others:

  • People with current respiratory conditions (e.g., allergies, asthma, or emphysema)
  • People with a compromised immune system (HIV/AIDS infection, organ transplant patients, or chemotherapy patients)

Always discuss your health concerns with your doctor, because the symptoms of mold exposure could be caused by other exposures and illnesses.

What are symptoms and effects of mold exposure?

Allergy and irritation are the most common symptoms of mold exposure. Less common effects of mold exposure include infections and illness. Serious infections from molds are relatively rare and occur mainly in people with severely suppressed immune systems. Illness has been reported from workplace exposures to mold. Although symptoms can vary, the most common symptoms seen in people exposed to mold indoors include:

  • Nasal and sinus congestion
  • Eye irritation, such as itchy, red, watery eyes
  • Wheezing and difficulty breathing
  • Cough
  • Throat irritation
  • Skin irritation, such as a rash
  • Headache

More Information:

Training and licensure of mold remediation contractors and abatement workers:

New York State Department of Labor
Mold Program
(518) 457-2735