A musty smell is usually the result of mould and mildew. The mould is usually caused by moisture, whether from water leaking into your living space, or wet objects, such as clothing, that do not dry properly. Humid conditions and lack of proper ventilation can also cause a musty smell. To get rid of the musty smell in your home, you need to get rid of the root cause. Some solutions are simple while others may require professional assistance.
Locate the source of the smell. Check common areas for moisture in your home such as the basement, inside the washing machine and dryer, and the bathroom.
Remove the object causing the smell, if possible. Re-wash clothing left in the washing machine or dryer. Remove water-damaged pieces of carpeting or upholstered items, such as cushions or furniture, exposed to moisture.
Open the windows. Mold and mildew thrive in areas with poor ventilation. Opening the windows also lets fresh air in and drives musty air out. Put fans backward in some of your windows to help pull air out of your living space.
Wash down hard surfaces, such as floors, bathroom walls and concrete floors with a solution of ¾ cup bleach in 1 gallon of warm water. Keep the windows open while using the bleach.
Hire a company that specialises in removing moisture and odours from floods and fires if odour remains.
To prevent musty smells in the future: Immediately transfer wet clothes from the washing machine to the dryer; seal leaky doors and windows to prevent moisture from seeping into the house; install a dehumidifier in the musty area (use a room dehumidifier for a small space, or a whole-home dehumidifier for a larger space); waterproof your basement.