Several suggestions of how to prevent mold

Keep the humidity level in the house low, below 40% if possible.
Throughout this web site the mantra is repeated; “Control the moisture and you control the mold”. Conversely, prevention of mold growth indoors cannot be achieved without proper moisture control.

Use an air conditioner or a de-humidifier during humid months.
In warmer months, air conditioning can de-humidify indoor air. But if the system is too large or too small for the space it serves, the cooling system can create high humidity by cooling without removing water vapor. A properly sized and maintained system will dehumidify and cool a building properly. In cooler months, water vapor can condense on cold surfaces in a building just as water condenses on the outside of a glass of ice water. Insulation of exterior walls can help prevent condensation and mold growth during the winter.

Always use exhaust fans.
Be sure the home has adequate ventilation, including exhaust fans in the kitchen and bathrooms. ALWAYS RUN THE EXHAUST FAN WHEN COOKING. Install bathroom fans that vent humidity to the outside. ALWAYS RUN THE FAN WHEN SHOWERING and allow the fan to run for 10-15 minutes after your shower.

Add mold inhibitors to paints before application.
When painting, apply multiple thin coats that dry fast and work with a de-humidifier.

Clean bathrooms with mold killing products.
When shopping for cleaning products look for ones that specify that they are MILDEWCIDE.

Do not carpet bathrooms and basements.
Carpeted bathrooms are mold breeding grounds. Use throw rugs and wash them as regularly as you wash towels. Do not use towels more than once or hang them to dry in a humid bathroom.

Never wet-clean carpets.
Always dry-clean carpeting. Mold under carpets typically requires that the carpets be removed. Once mold starts to grow in carpet, insulation or wallboard the only way to deal with the problem is by removal and replacement.

Vent your clothes dryer to the outside.
Clothes dryer vents are hot and humid air that creates the perfect mold growing environment.

Clean any moldy surfaces as soon as they are noticed.
Watch for signs of moisture, such as condensation on windows, cracking of walls, loosening of drywall tape, warped wood or musty odors.

Have your entire HVAC system cleaned annually.
Air duct systems can easily become contaminated with mold. Duct systems may be constructed of bare sheet metal, sheet metal with fibrous glass insulation on the exterior, or sheet metal with an internal fibrous glass liner, or they may be made entirely of fibrous glass. Bare sheet metal systems and sheet metal with exterior fibrous glass insulation can be cleaned and disinfected. If water damaged, ductwork made of sheet metal with an internal fibrous glass liner or made entirely of fibrous glass will often need to be removed and discarded. Ductwork in difficult-to-reach locations may have to be abandoned. If you have other questions, contact an air duct cleaning professional or licensed contractor.