Basement odor may develop and can be fairly difficult to remove. This odor is caused by mold and mildew which thrive in damp environments. Correcting the moisture problem is the most important step in removing the odor. When ground water seeps in around a basement’s walls and floor, mold and mildew can begin to grow. A foundation is rarely waterproof unless special steps are taken during construction. This means that the homeowners must waterproof the basement themselves. Using dehumidifiers, cleaning thoroughly, and sealing the basement walls and floors should alleviate the musty odor. Special care should be taken to seal any cracks and to caulk all corner joints in the basement.