Insulating Basement Heating Ducts - There are several approaches to help prevent moisture damage problems at a basement. The first rule of thumb is no dirt basements. Though these are less common in this day in age, it's good to point out that dirt flooring not only hold a huge amount of moisture but can also give off a variety of gases. When constructing a basement, make sure you have a floor drain with a trap installed in the lowest point of the ground.
With no floor drain, any water that's spilled inside can't escape. Sump pumps are often used where flooding due to a high water table might be a problem. In addition, waterproof the outside of the base walls and put in a perimeter drainage system. An often overlooked problem in bathrooms is moisture that comes out of humidity.
The simplest way to control humidity is to exhaust water vapor generated in the home to the outside. Indications of high humidity include condensation on windows, pipes or other surfaces as well a general awareness of moisture from the atmosphere, dampness, and smells. Often, the humidity will be caused by exposing the basement to outside air (open windows), using wet laundry hung to dry from the basement, storing firewood from the basement, or a drier vent that exhausts inside.
In summer, use a portable air conditioner or air conditioning to reduce humidity. In hot, humid weather, maintain basement windows closed. The key to keeping basement humidity is to keep them well ventilated and keep extra moisture out of the basement.