Basement Drain Smells Like Mildew - There are several ways to help avoid moisture damage issues in a basement. The very first guideline is no dirt basements. Though these are less prevalent in this day in age, it's good to point out that dirt flooring not only hold a large amount of moisture but also can give off a variety of gases. When building a basement, make certain that you have a floor drain using a trap installed in the lowest point of the ground.
Without a floor drain, any water that is spilled inside cannot escape. If necessary, install a sump pump and make sure that the sump cover is tightly sealed. Sump pumps are often used where flood because of a high water table might be a problem. Additionally, waterproof the outside of the base walls and install a perimeter drainage system. A frequently overlooked problem in basements is moisture that comes out of humidity.
The easiest way to control humidity would be to exhaust water vapor produced in the house to the outside. Indications of high humidity include condensation on windows, pipes or other surfaces as well an overall sense of moisture from the air, dampness, and odors. Often, the humidity will be brought on by exposing the basement to external air (open windows), having wet laundry hung to dry from the basement, storing firewood from the basement, and/or a drier vent that exhausts inside.
In hot, humid weather, maintain basement windows shut. Run the furnace fan continuously to circulate house air. The key to keeping basement humidity low would be to keep them well ventilated and keep additional moisture from the basement.