For most of us, a home is more than just four walls. It’s our most valuable asset; a structure that shelters those we love as well as precious belongings. And while homeowners desire a structure that is safe, hidden behind those walls could be an unhealthy presence—mold.

Mold remediation can cost homeowners thousands of dollars. Additionally, the high influx of mold-related claims has prompted some insurance companies to stop covering mold in their home policies. The best way to avoid a hefty bill and skyrocketing insurance payments is to help prevent mold before it starts.

Homeowners should be aware that mold thrives in moist, warm areas. In fact, mold can develop in as little as 24 hours after being exposed to water. A simple untreated water leak or an unvented shower can harbor a mold infestation.

To prevent mold, follow these guidelines:

Fix the Leak: If there is a leak in your home, fix it immediately. Leaks from water heaters, air conditioners, broken shower tiles and washing machines can cause serious water damage. Be sure to check these and other water sources on a regular basis.

Let Some Air In: One easy way to prevent mold growth is to reduce indoor humidity to less than 50 percent by using air conditioners and increasing ventilation in moisture prone areas around the house.) Note: If unsure about a home’s humidity level, consider purchasing a hygrometer, which is an instrument that measures the water vapor content in the air.)

Build Smarter: Paper is a food source for mold. When building or remodeling a home, consider using paperless drywall. This mold-resistant drywall incorporates glass mats on the surfaces of the drywall panel instead of paper facings found on traditional drywall. Typically, 70 percent of the interior surfaces in a home are comprised of drywall, so building or remodeling with paperless drywall is a sound decision that can help protect a home’s interior wall surfaces from the potential for mold development.

Build a Barrier: The Insurance Information Institute recommends painting the home’s exterior to help reduce the chance of moisture penetrating the home.

If you do find mold in your home, remove it immediately. Small patches of mold can be removed with a combination of water and detergent. If the patch returns, that can be a sign of an internal leak. For larger mold growths, consult a trained health and safety professional.