Mold: Another 800-Pound Gorilla

by Larry Wasson August 1, 2015

Every few years, more of these daunting beasts come along and change the way we inspect houses. They seem to arise out of nowhere, demanding that home inspectors successfully evaluate and report on them despite clouds of misinformation, confusion and controversy.

Our ever-changing troop of gorillas has included lead, Stablok breakers, UFFI, polybutylene and orangeburg pipes, electromagnetic fields, EIFS, radon, aluminum wiring, FRT sheathing, pinhole leaks, fire sprinkler systems, asbestos, pressure-treated lumber, Chinese drywall and CSST.

Two recent game changers are mold and mold-conducive conditions. When these upsetting giants are in the house, your customer can easily be distracted by confusing misinformation and meaningless comments such as “That’s just mildew” or “It’s not toxic black mold” or “It’s just a mold-like substance.”

Over the years, I have created a strategy to deal with each new 800-pound gorilla as it arrives. The results are information sheets that are updated as the facts change (for example, it took over 10 years for the true facts about polybutylene to be uncovered). These info sheets can and do help my customers make better decisions. An info sheet about mold would include these 10 points:

  1. Careful visual inspection is the primary and the best method for finding mold, mold-conducive conditions or both. You can always consult a professional mold inspector. Not knowing what mold looks like and not knowing where and how to look for mold are the reasons why people not present during an inspection fail to see the mold that is reported. Even large amounts of mold can be “invisible” in normal room settings. The same mold quickly becomes “visible” to all people present with the effective use of proper inspection procedures.
  2. Is it mold or a mold-like substance? Actually, there are very few mold-like substances; in most instances, if it looks like mold, it is mold. The most common uncertainty arises when mold is growing on or is mixed in dirt, deposits or other matter. Although many mold colonies are obvious, some are not easily recognized (for example, people often think that all that powdery or fluffy-looking stuff is just dust).
  3. When there is uncertainty, have the substance tested. Lab results will confirm whether samples contain mold (for example, molds listed with numerical spore counts are the molds present in the sample). The magnitude of spore counts has little meaning. Even samples taken nearby will have different spore counts and low spore counts do not mean low risk. If the report says mold is present, remove or remediate it as soon as possible.
  4. Mildews pose the same environmental and health risks as do molds, and environmental and health documents seldom differentiate between the two. Many varieties of Aspergillus mold are actually mildew and Aureobasidium, a common bathroom mold, is a mildew that causes skin irritation and asthmatic symptoms. So, whether it is mold or mildew, be sure to remove or remediate it as soon as possible.
  5. Toxic black mold is a very misleading term. There are toxic molds such as Penicillium that are not black, and there are black molds like Aureobasidium that are not toxic but are unhealthy. Of course, there are lots of unhealthy molds that are neither black nor toxic. All of these examples explain why all mold should removed or remediated as soon as possible.
  6. Air sampling is not a reliable method for determining whether mold is present. The U.S. Environmental Protection Agency (EPA) guide on mold, moisture and your home does not recommend or even mention air sampling; instead, the guide recommends careful visual inspection for mold. Air sampling is best used after all visible mold has been removed or remediated. Getting favorable air sample test results does not mean that there is no mold, and it does not mean that there is no risk. Using short-term air samples as a preliminary or primary method of checking for mold is as useless as trying to determine the risk of radon by using grab samples. In both instances, it is a gross misuse of short-term air sampling.
  7. If mold is present, it should be removed or remediated. Although it is common to find some minor indoor mold, active indoor mold growth is not common and is an unnecessary health risk. Whenever possible, mold should be removed; for example, using bleach to kill mold is not very effective, and dead mold will continue to release unhealthy spores. The reality is that even small amounts of mold can quickly become little spore pumps that seed unhealthy mold growth.
  8. If mold-conducive conditions such as water intrusion, excess moisture or humidity are present, they should be eliminated or remediated as soon as possible. EPA guidelines state that “indoor mold growth can and should be prevented.” Prevention means eliminating or remediating mold-conducive conditions. Two common methods of remediating moisture are bathroom exhaust fans with timer switches, and dehumidifiers installed in basements and crawl spaces. Correcting more complex conditions requires a commitment of time and effort, and remedies can be somewhat expensive.
  9. Follow EPA guidelines (www.epa.gov/mold/moldguide.html, and www.epa.gov/mold/mold_remediation.html). You could also consult a licensed, qualified remediator of mold and mold-conducive conditions, an industrial hygienist or both.
  10. Guard against and monitor for mold-conducive conditions. For example, install inexpensive humidity sensors with alarms and probes or inexpensive hygrometer systems with wireless sensors in attics, crawl spaces, basements, mechanical rooms, laundry rooms and other moisture-prone spaces.

To Read the Full Article

ASHI offers its members unparalleled resources to advance their careers. ASHI offers training for inspectors at all levels of knowledge and experience, including resources about all major home systems. Members benefit from a vast network of experienced professionals, providing a community for mentorship and knowledge sharing..

Learn More About Membership »

In this Issue

This field is for validation purposes and should be left unchanged.

Professional Networking

Grow your professional network, find a mentor, network with the best, and best part of the community that’s making home inspection better every day.