Mold: Is It Hiding in the Home You're Buying?

Recognize potential mold problems before buying a house and getthe seller's full disclosure for mold problems you can't see.

No one wants to buy a house with a mold problem. Unfortunately, these sneaky little spores aren't always easy to detect. If you're househunting, learn how to detect mold in homes, get the seller to disclose mold issues, and negotiate around any mold problems that come to light in the course of the sale. (To learn about mold in rental units, read Nolo's article Mold in Rentals: Landlord Liability, Responsibility, and Prevention.)

The Trouble With Mold in the Home

Mold is a fungus that comes in various colors (black, white, green, or gray) and shapes. While some molds are visible and even odorous, mold can also grow between walls, under floors and ceilings, or in less accessible spots, such as basements and attics. Mold does best in water-soaked materials (paneling, wallboard, carpet, paint, ceiling tiles, and the like), but can survive in almost any damp location. Mold can grow in houses situated in the desert, and it can grow in homes in hot and humid climes.

Here are some common places in a home where mold is likely to take hold:

• around leaking pipes, windows, or roofs (the constant supply of water gives mold spores the start they need)
• any place that's been flooded and hasn't been thoroughly dried
• tightly sealed buildings (common with new construction), which trap excess moisture inside, and
• in homes with poor ventilation, numerous over-watered houseplants, and housekeeping habits that ignore obvious dampness and don't include airing the place out.

Besides presenting an ugly appearance and, sometimes, an unpleasant odor, mold can cause health problems. In the worst cases, a few types of molds produce mycotoxins, which can cause rashes, seizures, unusual bleeding, respiratory problems, and severe fatigue in some people. Fortunately, most molds are of the non-toxic variety.

How to Detect Mold

You won't always know if there is mold in a house you're considering buying, but you can take a few easy steps to try and find out.

Be on the lookout for mold. When you're thinking about buying a home, look for the elements above to figure out if there are any obvious signs of mold or the potential for mold. Keep your eyes peeled for standing water in the basement, water marks on walls (particularly recent-looking stains), or musty smells (particularly in bathrooms, kitchens, laundry rooms, basements, cabinets with plumbing, or other areas with plumbing).

If you're looking at a newer home, find out whether it is built with "synthetic stucco," also called the Exterior Insulation and Finish System (EIFS). This airtight barrier is supposed to improve insulation but, if improperly installed, may allow water penetration and mold growth on the inside of walls.

Ask your home inspector. If you have the home professionally inspected before you buy it, your home inspector may see obvious signs of mold or water damage. While it's not the inspector's job to look for mold, most home inspectors will mention obvious signs of water damage and the possible presence of mold. And, because the inspector will poke around in spaces you might not, he or she may see things you wouldn't.

Don't hesitate to ask whether the inspector saw signs of mold or potential mold dangers, and ask that these results be included in the inspection report. Some inspectors may be wary of this, because they want to avoid liability for any mold-related problems. But all should be comfortable talking to you about whether they saw anything suspicious.

Ask the seller to disclose any mold or water-related problems.  Some states require sellers to disclose information about mold. Keep in mind that the seller's duty to disclose only relates to things the seller knows about or reasonably should know about he or she doesn't have a duty to go poking around in the walls to see if there's mold, for example. 

In states where mold disclosure is not required, you can still ask for such disclosure. In addition, ask questions about things that could lead to mold growth, such as "Have any pipes ever burst?" or "Have any of the windows ever leaked?"

Listen to agents and appraisers. In some states, real estate agents or brokers have a duty to disclose problems they know about. Likewise, an appraiser should notify you of any obvious sign of a mold problem if it could affect the value of the property.

Add a mold-related contingency to your offer. Assuming you're interested enough in the house to place an offer on it, making the sale contingent on your satisfaction with the results of specific inspections for mold lets you back out if the inspection finds a mold problem. Unfortunately, tests for mold are difficult to conduct and expensive. And, according to the U.S. Environmental Protection Agency (EPA), testing for mold isn't usually necessary when it's visible on surfaces. Most people will end up relying on the detection methods discussed above.

Nevertheless, if you have reason to suspect there's hidden mold in the home, you might elect to hire a professional mold testing company. These companies test the air in and around the home. They can also dig into walls and take samples, which they later test in a laboratory. Testing the air usually costs several hundred dollars. If the company takes wall samples, the cost will be even higher.

Should You Buy a House With Mold Problems?

If you find a house and discover it has mold problems, should you buy it anyway?  You'll have to decide whether the cost of removing the mold and fixing the source both in time and money is worth the price you'll pay. If you have an inspection contingency and the mold is revealed as part of the inspection, or if you have a specific mold contingency, you have a bargaining chip. You can ask the seller to reduce the asking price, to fix the problem, or you can choose to walk away from the deal. (To learn more about inspection contingencies, read Nolo's article Contingencies to Include in Your House Purchase Contract.)

For more practical homebuying tips, get Nolo's Essential Guide to Buying Your First Home, by Ilona Bray, Alayna Schroeder, and Marcia Stewart (Nolo).