The mold inspector you hire depends on your needs.

If you are worried about whether mold may be present due to a hidden leak, you want to hire a professional with experience investigating building problems. Use a mold inspector who owns a moisture meter and an infrared camera. Infrared cameras measure temperature differences, which can be caused by water evaporating from a damp surface. It’s important to use a moisture meter to confirm the presence of dampness, though, because temperature differences in a wall or ceiling cavity, for example, can also be caused by cooler air infiltrating the cavity.

A mold inspector who owns a borescope or even a mold dog may be what you need. A mold dog has been trained to detect the odor of mold growth. A borescope can be used to check for mold growth by looking through a hole in a wall or ceiling. And you want to hire a mold inspector who can take a sample through that hole.

If there’s a musty smell present, or if you see visible mold, you want to hire a mold inspector who can explain why the problem exists, the extent of the problem, and offer you recommendations for clean-up. Just be wary, however, of hiring someone who works for a mold remediation company, because although that person may have lower fees, the mold inspector may be interested in selling you a mold remediation job – which can cost thousands of dollars.

Any mold inspector you hire should have more training than a half-day course. Legitimate organizations that train mold inspectors include the Indoor Air Quality Association (www.iaqa.org) and the Environmental Solutions Association (www.esaassociation.com).

If you want to understand why and where mold grows, learn how to get rid of it and prevent it from returning, buy a copy of The Mold Survival Guide: For Your Home and for Your Health, Jeffrey C. May and Connie L. May (2004). Jeff May is also author of My House is Killing Me! The Home Guide for Families with Allergies and Asthma (2001) and co-author of Jeff May’s Healthy Home Tips (2008). All three books are published by The Johns Hopkins University Press and are available on amazon.com.