The ASHI Reporter recently spoke with Jeffrey C. May, mold expert and author of three books on mold and other indoor air quality (IAQ) issues. After 17 years as an ASHI inspector, May switched gears to become an IAQ professional and founded May Indoor Air Investigations LLC in Cambridge, Mass. He has investigated IAQ problems in thousands of structures, and he has a lot to say about mold.
Just how big is the mold issue?
“It’s really huge, enormous—I’ve been in over 1,000 sick buildings,” says May. While the ASHI Standards of Practice doesn’t cover IAQ issues, “inspectors need more trusted information, and they need to take the issue more seriously,” says May.
He sees a lot of denial in the industry, caused, he says, by insurance companies concerned that mold will become the next “asbestos,” leading to skyrocketing costs. But he argues that inspectors are on the front line and have the best chance of educating homeowners and improving the health of their homes—they owe it to their clients to address mold issues.
Mold spots proliferate on the subfloor of a house that was moved to a new site on a deep foundation that unexpectedly filled with water. The subfloor sat over a deep puddle during a damp fall, and by winter (long after the water had been drained), it was completely covered with mold. Photo courtesy of Jeffrey C. May
What are the main sources of mold?
“People get all bent out of shape from a patch of mold here or there, but the stuff that’s killing us is the stuff you usually can’t see, in the air conditioning system or carpets,” says May. In fact, whether you’re inspecting a residential or commercial property, he says, the air conditioning/heating system is most likely a source of mold contaminants.
Pull the cover off and look inside a blower cabinet, says May, and odds are good you’ll see as much as a half-inch of dirt and perhaps some stains. In those cases, there’s a “100 percent probability that there’s mold in there,” he says. “You can say, ‘use a better filter,’ but that’s not enough. A lot of times, the blower blades are covered with mold and spinning around,” he explains—continuously spraying mold spores into the air. “Every single home inspector should address at least the cleanliness issue with the client.”
Carpets are another primary source for microbial contamination. “If an inspector walks into a below-grade space and there’s a musty smell and the carpet looks like it’s been wet, it’s got to go,” says May. “Those carpets shouldn’t be washed; you can’t get rid of contaminants that way,” he explains. If in doubt, the home inspector should recommend that the carpet dust be tested for mold.
Construction debris was left by builders in a relatively new house that now has indoor air quality problems. Photo courtesy of Jeffrey C. May.
What tools can inspectors use when searching for mold?
A bright flashlight and a couple of mirrors (including an extending flame mirror with a glass mirror attached to the steel with double-stick tape) will be useful in hunting for mold on top of ceiling tiles, in dirty ducts and other tricky spaces. May also suggests using a non-invasive moisture meter that can check stains for dampness.
In a day care center hallway, groundwater leakage through the foundation wall caused stains on the floor, and water soaked into the drywall, causing extensive mold growth (showing up in the spatter patterns). Photo courtesy of Jeffrey C. May.
Should inspectors perform mold testing?
No, says May. “I would no more recommend that indoor air quality be a part of a pre-purchase home inspection than I would suggest someone with a brain tumor go to a heart specialist for surgery,” he says.
Searching for visible mold and air testing for mold are very different, May explains. Testing goes beyond the ASHI standards of practice and requires scientific training. Even if a home inspector has had such training and is able to test for mold, mold testing should not be part of the home inspection service.
Instead, May recommends that inspectors bring in a qualified expert to test for mold and other contaminants. Qualified is a key word here: “Moldy onions can cause high readings,” says May, or an inspector who has been in a moldy attic or crawl space in one home may carry spores into the next home he visits. “Bring in an expert,” says May, someone with experience who can not only detect the presence of mold, but can also determine what’s causing the problem and make recommendations for mitigation.
Visible mold is always a sign of an underlying problem, May concludes, but it is not the inspector’s job to identify the type of mold or determine if it is toxic. In May’s opinion, however, it is part of the inspector’s responsibility to supply his or her explanation as to why visible conditions might lead to excess moisture in the home.
Prospective homebuyers walked away from this home because of a pervasive musty smell. The source of the odor: rampant aspergillus mold (all the black color). Photo courtesy of Jeffrey C. May.
Finding an Expert
After explaining that the ASHI Standards of Practice and Code of Ethics excludes indoor air quality issues, some inspectors would like to help their clients find additional information.
Jeff May suggests home inspectors who want to refer their clients to an expert post an inquiry on the Indoor Air Quality bulletin board at email@example.com, or look at the American Industrial Hygiene Association’s Web site: www.aiha.org.
The Indoor Air Quality Association (iaq.org), recommends hiring a company with qualified and certified staff that will be following industry standards and guidelines to ensure a job done right. It recommends and endorses the certification programs of the American Indoor Air Quality Council (AmIAQ), an independent certification body.
From the Home Inspector’s Point of View
OK, so you've discovered a moisture problem with some black stuff growing on it. What now? Is it really a health problem? Finding someone to give meaningful answers is not as easy as it seems.
First and last, remember that mold growth is a sign of a moisture problem. If the moisture problem is not identified and corrected, then the mold will just come back no matter what else is done. Finding the moisture source is the one area where home inspectors should be offering their customers some advice.
Beyond that I believe addressing the health effects of mold should be left to a health professional, specifically an industrial hygienist. The American Industrial Hygiene Association (AIHA) Web site offers a search tool to find a consultant at www.aiha.org/ Content/AccessInfo/consult/. This includes a feature that allows consumers to find an expert in specialty areas such as mold or indoor air quality.
Since credentials vary widely, I caution my clients to do extensive research if they believe they need to consultant an expert about mold.
—Garet Denise, ASHI technical committee chair
Consumers and home inspectors both may be interested in what the Center for Disease Control and the Environmental Protection Agency have to say about mold.
Mold and Your Health
Exposure to damp and moldy environments may cause a variety of health effects, or none at all. Some people are sensitive to molds. For these people, molds can cause nasal stuffiness, throat irritation, coughing or wheezing, eye irritation or, in some cases, skin irritation. People with mold allergies may have more severe reactions. Immune-compromised people and people with chronic lung illnesses, such as obstructive lung disease, may get serious infections in their lungs when they are exposed to mold. These people should stay away from areas that are likely to have mold, such as compost piles, cut grass and wooded areas.
For more from the CDC, visit www.cdc.gov/mold/dampness_facts.htm.
From “A Brief Guide to Mold, Moisture, and Your Home”
Testing or Sampling for Mold
Is sampling for mold needed? In most cases, if visible mold growth is present, sampling is unnecessary. Since no EPA or other federal limits have been set for mold or mold spores, sampling cannot be used to check a building’s compliance with federal mold standards. Surface sampling may be useful to determine if an area has been adequately cleaned or remediated. Sampling for mold should be conducted by professionals who have specific experience in designing mold sampling protocols, sampling methods and interpreting results. Sample analysis should follow analytical methods recommended by the American Industrial Hygiene Association (AIHA), the American Conference of Governmental Industrial Hygienists (ACGIH) or other professional organizations.
To read the entire guide and find other information on mold, visit www.epa.gov/mold/moldguide.html.