Kill mildew before it has a chance to grow

By Morris and James Carey For AP Weekly Features
Friday September 28, 2001



Q. Julie asks: I have a mildew problem on the ceiling above my shower. I do not have a window in the bathroom. I want to paint, but am worried it might just be covering a problem instead of repairing it. I use bleach about every two weeks to clean the ceiling and walls, and it does make the appearance of the mildew go away for a few days. What would be the best thing for me to do? 

A. Mildew in your home is easy to remove. Just mix one-third cup of powdered laundry detergent (less if concentrated) and 1 quart of liquid chlorine bleach with 3 quarts of warm water. Add the bleach to the water first and then the detergent. Scrub with a bristle brush, and in minutes the mildew will disappear. Rinse the area thoroughly and towel-dry. Although this reasonably mild solution can be used for most painted surfaces, you’ll want rubber gloves, eye protection and plenty of ventilation. 

But why spend time removing mildew when you can prevent it? Mildew can’t grow without a food source, and the food source that mildew thrives on is moisture. Mildew spores are in the air everywhere. They look for moist places to settle, feed and grow. 

How do you prevent mildew from growing? Reduce or eliminate the food source by cutting down on the amount of moisture, usually condensation, which settles on walls, floors and ceilings. This might not be as simple for someone who lives in Florida as for a family in west Texas, but, given varying degrees of attention, eradication is possible even in relatively humid climates. 

That you don’t have a window in your bathroom means that ventilation might be poor. Moreover, the lack of natural light provides optimal conditions for mildew growth. 

According to the Building Code, a bathroom without a window must have an exhaust fan to remove moisture and odors. Unfortunately, bath fans are often undersized, broken or simply not used. If you have an exhaust fan, make sure that it is cleaned periodically, that the duct is properly connected and in good shape and that it is always used during showering and allowed to run for 10 to 15 minutes after the shower is over. Also, check the CFM rating on your fan housing (that’s the amount of air that the fan moves expressed as cubic feet per minute); anything less than 80 cfms usually is too small for most American bathrooms. Consider upgrading to a larger model, if such is the case.