MOLD: A Problem in Your Home?

Mold in Homes

Given the amount of rain from recent storms, I thought some tips on how to protect your home and ultimately yourself and your family from mold would be helpful.

You will find more complete information on the Minnesota Department of Health (MDH) website. Go to click on “Topics,” click on “Environments and Your Health.” Scroll down and click on “Healthy Homes in Minnesota, and then “Mold and Moisture.” There are many other topic areas you may find helpful as well.

So what are the Health Concerns of Mold?
Health effects from exposure to mold can vary greatly depending on the person and the amount of mold in their home. Health symptoms that may occur include coughing, wheezing, nasal and throat conditions. People with asthma or allergies who are sensitive to mold may notice their asthma or allergy symptoms worsen. Individuals with severely weakened immune system who are exposed to moldy environments are at risk of developing serious fungal respiratory infections. However the long term presence of indoor mold growth may eventually become unhealthy for anyone. MDH recommends that people consult a medical professional if they are concerned about the effects of a moldy environment on their health.

Are some molds more hazardous than others?
Many molds can produce potentially harmful substances, whether it’s allergens, mycotoxins, or other compounds. Hence, all indoor mold growth should be removed promptly, no matter what type(s) of mold is present or whether it can produce toxins.

How do I tell if I have a mold problem?
Investigate don’t test. The most practical way to find a mold problem is by using your eyes to look for mold growth and by using your nose to locate the source of a suspicious odor. If you see mold or if there is an earthy or musty smell, you should assume a mold problem exist. Mold often appears as discoloration, staining, or fuzzy growth on the surface of building materials or furnishings. Look for signs of excess moisture or water damage: leaks, standing water, water stains or condensation problems. Search behind and under carpeting, wallpaper, vinyl flooring, sinks, furniture or stored items-especially things placed near outside walls or on cold floors.

MDH does not recommend testing for mold. Instead you should simply assume there is a problem whenever you see mold or smell mold odors.

The following information about mold clean-up is lengthy but thorough. To clean up and remove indoor mold growth, follow steps 1-6 as they apply to your home.

1. Identify and Fix the Moisture Problem – the most important step in solving a mold problem
is to identify and correct the moisture source(s) that allowed the growth in the first place. Common indoor moisture sources include:
Condensation (caused by indoor humidity that is too high or surfaces that are too cold)
Roof and plumbing leaks
Firewood stored indoors
Humidifier use
Inadequate venting of kitchen and bath humidity
Improper venting of combustion appliances
Failure to vent clothes dryer exhaust outdoors (including electric dryers)
Clothes line drying indoors

To keep indoor surfaces as dry as possible, try to maintain the home’s relative humidity between 20-40 percent in the winter and less than 60 percent the rest of the year. You can purchase devices to measure relative humidity at some home supply stores. Ventilation, air circulation near cold surfaces, dehumidification, and efforts to minimize the production of moisture in the home are all very important in controlling high humidity that frequently causes mold growth in our cold climate.

2. Begin Drying All Wet Materials – as soon as possible after becoming wet. For severe moisture problems, use fans and dehumidifiers and move wet items away from walls and off floors. Check with equipment rental companies or restoration firms for additional equipment or contracting options.

3. Remove and Dispose of Mold Contaminated Materials – items which have absorbed moisture (porous materials) and have mold growing on them need to be removed, bagged and thrown out. Such materials may include dry wall, insulation, plaster, carpet/carpet pad, ceiling tiles, wood products (other than solid wood), and paper products. Likewise, any such porous materials that have been in contact with sewage should also be thrown away. Non-porous and semi-porous materials with surface mold growth may be saved if they are structurally sound (see step 4).

Take Steps to Protect Yourself – the amount of mold particles in air can increase greatly when mold is disturbed. Consider using protective equipment when handling or working around mold contaminated materials. The following equipment can help minimize exposure to mold:
Rubber gloves
Eye goggles
Outer clothing (long sleeves and long pants) that can be easily removed in the work area and laundered or discarded
At a minimum, you should use an N95 or a N100 type disposable respirator. Where mold growth is very heavy or covers an extensive area or if you are sensitive to airborne contaminants, greater respiratory protection may be more appropriate. More protective options include half-face negative-air respirators with a HEPA filter (i.e., N100, P100).

Take Steps to Protect Others – plan and perform all work to minimize the amount of dust generated. Where possible, consider the following actions to help minimize the spread of mold spores:
Enclose or contain all moldy materials in plastic (bags or sheets) before carrying through the home.
Hang plastic sheeting to separate the work area from the rest of the home.
Cover supply and return vents in the work area.
Place fans in windows of work area to pull contaminated air out of the work area and exhaust it to the outdoors.
Operate an air scrubber, which can be rented at cleaning supply companies.
Remove outer layer of work clothing in the work area and wash separately or bag
Damp clean the entire work area to pick up settled mold spores in dust.

4. Clean Surfaces – surface mold growing on non-porous or semi-porous materials such as hard plastic, concrete, glass, metal, and solid wood can usually be cleaned. Cleaning to remove and capture all mold contamination, is very
important because dead spores and mold particles may cause health problems if they are left in place.
Thoroughly scrub all contaminated surfaces using a stiff brush, hot water and a non-ammonia soap/ detergent or commercial cleaner.
Collect excess cleaning liquid with a wet/dry vacuum, mop or sponge
Rinse area with clean water and collect excess rinse water.

5. Disinfect Surfaces (if desired) – after cleaning has removed all visible mold and other soiling from contaminated surfaces, a disinfectant may be used to kill mold missed by the cleaning. In the case of sewage contamination, disinfection is strongly suggested–contact the Minnesota Department of Health for appropriate advice.
Mix 1/4 to 1/2 cup bleach per gallon of water and apply to surfaces where mold growth was visible before cleaning. Apply the solution with a sponge or by other methods that do not over saturate or flood the surface area.
Collect any run-off of bleach solution with a clean and filtered wet/dry vacuum, sponge or mop. However, do not rinse or wipe the bleach solution off the areas being treated — allow it to dry on the surface.

Always handle bleach with caution. Never mix bleach with ammonia — toxic chlorine gas may result. Bleach can irritate the eyes, nose, throat, and skin. Provide fresh air (for example, open a window or door). Protect skin and eyes from contact with bleach. Test solution on a small area before treatment, since bleach is very corrosive and may damage some materials.

6. Remain on MOLD ALERT – Continue looking for signs of moisture problems or return of mold growth. Be particularly alert to moisture in areas of past growth. If mold returns, repeat cleaning steps and consider using a stronger solution to disinfect the area again. Regrowth may signal that the material should be removed or that moisture is not yet controlled.

When can we rebuild?
Rebuilding and refurnishing must wait until all affected materials have dried completely. It may take several days or weeks for building materials to fully dry and return to prior moisture conditions. A moisture meter may help measure drying progress.