Mold In Your Home: Cleaning
Before you clean
Before cleaning mold in your home, first understand why it's there and fix
the problem causing the mold growth. This will require a thorough
inspection. Fungi (or mold) need a source of moisture, a source of organic
matter, and proper temperature. Areas inside your home that have poor air
movement and a source of moisture are likely areas for mold growth.
Once the source of the water intrusion and the food source have been
found, they should be addressed to prevent future mold growth. If this is
not done, mold may return. You must either eliminate or ventilate the
source of water or moisture. Affected building materials, such as carpets
or drywall, may need to be replaced.
If I see mold in my home should it be tested?
Testing for mold is generally not necessary. If you can see and smell
it, you have a mold problem. However, it is recommended that you do
have a thorough inspection to determine the cause of the mold growth.
DHS recommends that you hire a consultant specializing in building
assessments to evaluate your entire house.
Here are IAQ consultants and mold remediation contractors
whose primary focus is mold:
How can I clean up mold in my home?
Occasionally, mold can be found in the bathroom, on a windowsill,
shower curtain, or wall. This mold can be wiped off the surface with a
damp cloth and cleaning agent (e.g. window or bathroom cleaner).
Preventing mold growth requires controlling the moisture source. This may
be as simple as using a dehumidifier or fixing a simple leak. For larger
mold problems (about 10 square feet), follow the three (3) phases below: (If
you feel that the following guidelines are too vigorous, you should
contact a mold contractor to complete the clean-up.)
Gather the following items:
- Plastic sheets to cover door openings, windows floors and vents (the
plastic should be at least 4 mm in thickness)
- A breathing respirator (to cover mouth and nose) with HEPA cartridges
(available at most home fix-it stores)
- 3 spray bottles/plant misters
- Paper towels or disposable rags
- Heavy duty plastic garbage bags
- General household cleaner (only use cleaners without ammonia)
- Regular household bleach (between 1% and 5% chlorine) Please
Note: Bleach is typically not necessary to clean up mold, unless a
sewage release occurred. In this case, both mold and bacteria can
be reduced using a bleach solution as a final disinfecting rinse.
- Latex (non-latex if you are allergic to latex) or rubber gloves and
- A one-cup measuring container
- 3 buckets that will hold at least a gallon of water each
- Commercial grade HEPA-Vacuum. Do not use a home vacuum since it is not
designed for this type of work. Contact your
Local Health Department to
find out where to rent a HEPA-Vacuum in your area.
- Dehumidifier. Do not use a fan since it can cause mold spores to be
WARNING: Do not mix
bleach with other household cleaners. Some household cleaners
contain ammonia. If ammonia is mixed with chlorine bleach, a
toxic gas can form, causing serious injury or death.
- Mix general household cleaner and water in a bucket and transfer to a
spray bottle (follow manufacturer’s instructions).
- If bleach use is desired due to a gray (laundry) or black (sewage)
water release, prepare a bleach solution in a separate bucket. Using gloves and
goggles, add one cup (8 ounces) bleach for every gallon of tap water. Bleach (the active ingredient is
chlorine) can reduce mold and bacteria on treated surfaces.
- Transfer the bleach solution into the 2nd spray bottle
(use gloves and goggles).
- Pour clean, warm, rinse water (no bleach or household cleaner
added) into the 3rd spray bottle.
Application and cleaning phase
CAUTION: The bleach
solution is irritating and harmful to the skin, eyes, and
clothing. Avoid direct contact with the bleach by wearing rubber
gloves, respirator and goggles during the entire mixing and
Before you begin:
- Seal off the room from the rest of the house with the plastic
- Keep children and animals out of the work area during the
- Do not eat, drink, chew gum/tobacco or smoke at any time during
- Use a dehumidifier prior to, during, and after the clean-up to
keep areas dry and prevent mold from reoccurring.
- Spray and remove visible mold with general household cleaner
solution. Start from the top and work down. Change towels
frequently. Discard towels in plastic bag. Rinse the same area with clean
water on a damp towel or lightly spray with warm rinse water in a spray
bottle and wipe with a clean towel.
- Repeat the above step until all visible mold is gone. Note: There may
be some discoloration of the surface from both the mold and the cleaning
solution. Take care to avoid damaging the surface by cleaning too hard.
- If a bleach solution is to be used, wipe the affected area and let
set for 15 minutes (for fungicides other than bleach,
follow the manufacturer’s instructions). Rinse the area with a damp
towel using clean warm water or by lightly spraying with warm rinse water
in a spray bottle and wiping with a clean towel.
- Once the surface is dry to the touch, HEPA Vacuum for at least 1
minute per square foot of affected area. Dead mold and spore bodies can
still be highly allergenic to susceptible individuals, so thorough HEPA-vacuuming
is necessary to remove all mold fragments. Place HEPA-vacuum bag into a
garbage bag (follow manufacturers guidelines for using a HEPA-Vacuum).
- Tightly tie the garbage bag and dispose of it as you would your
everyday household garbage.
- Flush wastewater down a toilet, utility sink, or floor drain.
- Change out of your cleaning clothes. Wash your hands and face.
- Wash your cleaning clothes separate from your family’s laundry.
- At this point, you can apply paint or other coating to the surface.
You may wish to use a paint/coating that contains a mildew-cide or
fungicide to prevent future mold growth. Be sure to follow the
manufacturer’s instructions and recommendations when using any mildew
resistant paint or paint additive. Remember, these are also pesticides,
and may have adverse health effects on some individuals.
Note on Use of Ozone Air Cleaners
Do not use ozone air cleaners to kill
mold. Ozone air cleaners generate ozone: a known respiratory
irritant. The USEPA
(exit DHS) does not recommend using ozone generating air
cleaners for treating indoor mold problems.
If a contractor or a consultant recommends the use of an ozone
generating air cleaner to treat a mold problem in your home, please
file a complaint online with the
Wisconsin Department of Agriculture,
(exit DHS) or at 1-800-422-7128.
Be sure to include as much information as possible.
For more informationFor health related questions, contact the Division of Public Health, Bureau of
Environmental and Occupational Health,
PO Box 2659, Madison, WI 53701-2659,
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