Mold grows by consuming other organic material. When they consume cellulose in wood and the paper covering of drywall, it can be destructive to the structural integrity of the building.
Mold can rot clothing, destroy books, and make bread, fruit, vegetables, and cheeses inedible.
Mold can trigger asthma attacks or cause allergic reactions in some people.
For many of us, at the point where we first notice it, mold is just plain unsightly.

Mold Control: Prevention

Mold requires available moisture above specific levels that varies by the species of mold in order to grow. The mold will produce spores that may exist in much drier environments and this dormant spore may survive for quite some time.

Mold spores will not develop into actively growing organisms until they encounter sufficient moisture for them to grow. Bread will develop mold when kept inside a plastic bag. Put a slice of bread on the kitchen counter here in Utah and it will dry out; there will be no further development of mold.

The humidity levels commonly encountered in Utah do not support mold growth. Leaks in plumbing, roofing, and foundations are common sources of moisture that will support mold growth. A less well recognized source of moisture is condensation. This condition is mostly associated with cold winter weather.

Water condensation can be seen in the summer on the sides of a glass containing iced beverages. Warm air can hold more water vapor than cold air. Warm air is chilled when it contacts the cold beverage glass and the moisture in the air condenses onto the outside of the beverage glass.

This same process occurs in the winter when the warm air inside your dwelling is chilled when it comes in contact with a cold outside wall, window pane, or metal window frame. The goal is to not allow the air to stay in contact with the cold surface long enough tobecome chilled to the point of allowing condensation.

This can be done either by reducing the water content of the air or moving the air so it does not have time to become sufficiently chilled. Increasing the insulation in these outside walls, windows and window frames is another option but rather expensive to accomplish.

Moving Air

Opening a window even a small amount can create enough circulation of air to reduce condensation. This seems counter productive in the winter when it is cold outside but it works. The outside air has less moisture than the air indoors.
Moving furniture drapes, and clothing away from these outside walls three to six inches can allow for adequate air circulation.
Retrieving the fans that you put away for the winter and using them to move air in some rooms is also effective. This can feel cold but can be used in rooms when they are not being occupied.

Reducing moisture

Check that there are no leaks in the roof, plumbing, or foundation. Fix any leaks you find.
Look for obvious sources of water such as indoor water falls, dripping faucets, house plants. It may seem there is not much you can do about the standing water in the toilet but keeping the lid down may help. Consider how you can minimize any other sources of water.
Do you have a clothes dryer? Is it vented to the outside and not just to a void in the basement, crawl space or attic?
Showers put more moisture in the air than baths. Do you use the mechanical ventilation and/or open a window while showering? OK, that’s cold, but you can vent the moist air as soon as you are dry and continue to run the vent for a while after you are out.
Winter is sweater weather. Do you air dry sweaters or other laundry in the house? This puts a lot of moisture into the air.
Do you have a dishwasher? Have you noticed the steam during the dry cycle? That is a lot of moisture going into the air.
Meals that involve boiling can put a lot of moisture in the air. Soups and pastas result in a lot of moisture in the air. If your stove hood vents to the outside, use it during cooking. If it vents back into the room it will not help much with the moisture issues.
Regarding bathroom mold: If surfaces are wet for a couple hours but dry for most of each day, you can reduce the mold growth. Families that spread their showers out over the course of the day may have more mold growth in the shower than those families whose members all bathe within a few hours and allow the surfaces to dry thoroughly until the next day. Using a squeegee and towel on the walls after the last shower will reduce the moisture evaporating into the air even more.
If you are using cloths to sop up the water that has condensed on the window sill, toss the cloths into the dryer each day rather than air drying.

You will never eliminate all the moisture nor do you want to. Just breathing puts a lot of moisture into the air. Really low humidity levels can be very unpleasant to the membranes of the nose and mouth. Use a combination of the air movement and moisture reduction items that work for you.

Mold Control: Removal

It won’t do much good to remove mold and not remove the source of water that allows that growth in the first place. Mold spores are everywhere. You really can’t eliminate them. What you can do is eliminate or control the conditions that allow molds to grow. There aremany different kinds of molds and they have different moisture requirements.

Review the steps mentioned in the section “Mold Control: Prevention” and decide what you can do to control the growth of mold. Then address the issue of removal. In most situations, the problem is recognized before it is so out-of-hand that you need a professional to address the issue.

If you could pull all the mold colonies on any one wall together, would the area exceed a 10 foot by 10 foot blotch? If so, it may be time to consult a professional. Review the recommendation of the Centers for Disease Control and Prevention and the Environmental Protection Agency.

Even if the area is not that large, you will want to consider the following: If you can take a walk in the Fall and kick up the leaves with abandon, you can probably clean up anything less than 100 sq feet yourself. If the thought of kicking up leaves horrifies you because of the allergic reaction or asthma attack you experienced in the past, ask someone else to do the removal.

For those of us that caught the situation at a reasonable stage and have no known adverse reaction to Fall hikes, you may be able to tackle the problem with your favorite household detergent. After removing the mold, dry the area and keep it dry.

If some staining remains, then you may want to consider a bleaching solution. Follow the directions on the container. Be sure to dry the area thoroughly. You are doing this to remove stains not to kill the mold. Keeping the area dry will kill the mold. Spores will still be lurking about and will begin to grow if and when the moisture returns.

A word to renters

If the moisture is from structural or plumbing leaks the landlord is responsible for repairing the structural or plumbing deficiencies. If the moisture is from condensation, the tenants are responsible for the lifestyle changes needed to control the problem. The tenant also has a responsibility to inform the landlord of any mold growth due to structural or plumbing leaks as soon as the tenant becomes aware of the leak or mold, which ever is first.