How Humid Should My Basement Be?

Basement humidity that's too high can create mildew and mold problems. This is rarely a concern in the winter since the colder air doesn't retain humidity, but during a rainy spring or summer the humidity can spike quickly. The basement humidity should be kept at or below about 65 percent during the summer and 30 to 40 percent in cold winter climates, according to Dr. Kenneth Hellevang from North Dakota State University. There are several ways to help keep it at those levels.

Things You'll Need

• Electronic hygrometer
• Dehumidifier
• Fan

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Instructions

1. • 1

     Set a electronic hygrometer in the basement to measure the air moisture content. Keep a watch on it to see if your home has a problem.

   • 2

     Run a dehumidifier as the best way to remove basement air moisture. A model with a continuous drain never needs emptying, while some models can be set to operate only when the moisture level reaches a predetermined amount.

   • 3

     Provide for air circulation via a table or exhaust fan. Leave room between the walls and the furniture so the air can move freely about the room.