Summer Humidity and Mold in Northwest Indiana

Mold does not only come from leaks and floods. Plenty of the mold we see in the summer comes from nothing more dramatic than humid air sitting in a space that cannot dry out. In Northwest Indiana, our proximity to Lake Michigan means we get long stretches of warm, humid weather, and that humidity does not stop at the front door. It settles into basements, closets, and any corner of the house that stays cool and still.

Why humidity alone is enough

Mold needs moisture, and water vapor in the air counts. When indoor humidity climbs and stays high, moisture condenses on cooler surfaces like basement walls, the inside of exterior closets, and around windows. Those surfaces stay damp enough, long enough, for mold to take hold even though there was never a leak or a flood. The U.S. Environmental Protection Agency recommends keeping indoor humidity below roughly 60 percent, and ideally in the 30 to 50 percent range, specifically to discourage mold growth. In our climate, summer is when that number is hardest to hold, and high humidity is one of the most common reasons mold keeps coming back after it is cleaned.

The spots that get hit first

The pattern is consistent. Basements are the usual leader, because they are cool, often under ventilated, and naturally damp. After that come closets on exterior walls, bathrooms without good ventilation, areas behind furniture pushed tight against cool walls, and any room that gets closed up and ignored for weeks at a time. Stagnant, humid air is the common thread.

How to keep ahead of it

The good news is that humidity is manageable, and prevention is far easier than dealing with mold after it grows. A few habits go a long way through the summer:

• Run a dehumidifier in the basement and empty or drain it consistently. This is the single most effective step for most homes here.
• Use exhaust fans in bathrooms and the kitchen, and let them run a while after you are done.
• Keep air moving. Stagnant air is mold's friend, so a fan or open interior door in a closed up room helps.
• Pull furniture a few inches off cool exterior walls so air can circulate behind it.
• Address any small leaks or condensation promptly rather than letting them linger.

When prevention is not enough

Sometimes you do everything right and still notice a musty smell or surface growth by August. If that happens, it is worth finding out whether it is a localized spot or a sign that humidity has been feeding something larger, including the kinds of mold we describe in our post on black mold as a hidden threat. Our indoor air quality and mold testing can tell you where you actually stand, and if growth has already taken hold, mold remediation addresses it along with the conditions that allowed it. Lasting prevention is really a mold mitigation question, which is just a fancy way of saying keeping things dry. We would always rather help you prevent a problem than fix one. If you are seeing the early signs this summer, call us at (219) 779-8198 and we will help you sort out whether it is a quick fix or something to look at more closely.

Humidity guidance referenced from the U.S. Environmental Protection Agency.