What to Do When You Suspect Toxic Mold Has Invaded Your Home

a gloved hand cleaning mold from a white ceiling with a pink and green sponge

Every home has mold inside it, no matter how clean it is. Every time you go outside or open the windows, you encounter mold spores. Some spores are relatively harmless; others can be forms of toxic or black mold, also known as strachybotrys. When toxic mold enters your home and finds a place to grow, it begins to produce mycotoxins that can cause health problems. Sometimes the only visible sign of a mold infestation are the health problems that the inhabitants suffer. These health problems usually manifest themselves as headaches, eye or nose irritation, coughing, sneezing, and other respiratory problems. However, before you run out and purchase an expensive test for black mold, you should know a little more about it.

Limit Moisture

First, mold cannot grow without water. If you eliminate the water source, you will eliminate the mold. Black mold requires more water to grow than other types of mold. In a home environment, sources of this water can come from leaky roofs and gutters, sprinklers that spray onto the building, plumbing leaks, condensation, or water vapor. Water vapor is produced naturally anytime you cook, bathe, wash the clothes, water the plants, or even breathe.

One or more of these conditions could apply to any house, but not all of them will have a problem with mold. Houses should be inspected for mold if they smell moldy without a visible source or if there has been problems with flooding, leaks, excessive moisture, or water damage. Homes that are inadequately ventilated or insulated can also have trouble with mold.

Check Problem Areas

If you suspect a mold problem, the first thing you need to do is investigate. Investigating is much cheaper than testing and may be able to tell you what you need to know. If you see or smell mold, it is pointless to test for it; and your attention should go toward cleaning it up instead. Mold is really good at hiding. You have to look thoroughly. Some places you need to check are:

1. Backsides of dry wall, wallpaper, or paneling

2. Top sides of ceiling tiles

3. Undersides of carpets and pads

4. Inside walls around pipes that are or produce condensation

5. Walls and floors behind furniture where condensation can form

6. Inside ductwork

7. In roof materials above ceiling tiles

mold hiding behind a wall cover

Use both your eyes and your nose to check. Look for any visible mold growth. It may appear cottony, velvety, granular, or leathery and can vary in color from white, to gray, brown, black, yellow, or green. Look for signs of excessive moisture or water damage such as standing water, watermarks, and discoloration on the walls, ceilings, carpets, or woodwork. If you find an area with a noticeable mold smell or one that has water damage, you may need to use destructive techniques to inspect enclosed areas such as wall cavities where mold could be hiding.

If you do not find any signs of mold, you probably do not need to test for it. In general, mold testing should only be done if there is pending litigation or health concerns, as part of a real estate transaction, or if the sources of a mold contamination are unclear.

Identify the Source and Dry It

If you find mold, two things need to be done. First, you need to determine the source of moisture that is allowing the mold to grow and stop it. Second, you need to eliminate and clean up the mold. Once you have stopped the source of the moisture, make sure you dry everything out before you begin cleaning. Using fans and dehumidifiers will usually help speed the process. However, do not use fans if mold is visible because it can cause the mold spores to spread.

Once things are dry, it is time to clean or dispose of any moldy materials. Make sure you wear protective material when you are doing any mold clean up. This includes rubber gloves, eye goggles, a long sleeve shirt, long pants, and a medium- or high-efficiency filter dust mask. Before leaving the contaminated area, remove your clothes and put them in plastic bag to be laundered or discarded. Otherwise, you could spread mold spores through your home.

If the moldy items are porous, your only option is to dispose of them. Some examples of porous materials include plasterboard, insulation, plaster, carpet, carpet pads, ceiling tiles, paper products, and some wood. You only need to throw away the items if mold is visible. Make sure all items are bagged before being transported through the house.

a woman looking at mold on a wall and holding hands over her nose and mouth

Clean the Surfaces

If the material is non-porous or semi-porous, you may be able to clean them. Examples of non-porous or semi-porous items include glass, concrete, hard plastic, metal, and solid wood. Cleaning the item should start with a HEPA vacuum to remove as much contamination as possible. The standard household vacuum or shop vac will not work unless it has a high-quality HEPA filter installed on it.

If you can't get a HEPA vacuum, wipe the item off with a damp cloth. Rinse the cloth often and dispose of it when you are finished. After you have removed as much of the mold as possible using the vacuum or cloth, it is time to scrub. All contaminated surfaces should be scrubbed with a stiff brush, hot water, and a non-ammonia soap or commercial cleaner. Use a wet/dry vacuum or sponge to collect any excess cleaning water. Rinse the item with clean water and dry everything as thoroughly and as quickly as possible.


You may want to follow up by disinfecting the surfaces to kill any remaining mold. Use a mixture of one-half cup bleach per one gallon of water and apply it to any surfaces where mold was growing. Allow the bleach water to air dry on the surface, but use a wet/dry vacuum or sponge to collect any run-off.

Stay Vigilant

After everything has been cleaned and dried, you will need to continue to watch for signs of moisture or new mold growth. If the mold returns and you are positive you do not have a moisture problem, you have a couple of options. You can repeat the cleaning process with a stronger disinfecting solution or contact a professional cleaner to come in. However, it might be easier, cheaper, and more effective to get rid of the contaminated material.

Mold will not cause major problems, provided you take action immediately. Most problems with mold are easy enough for people to fix themselves. Remember, the Environmental Protection Agency advises people to investigate before testing and then clean mold contamination themselves. Only in rare circumstances will they recommend paying for these services. Do not be duped into purchasing an expensive and needless test. It is foolish to pay someone else to do a job that you are capable of doing it yourself.