Healthy Indoors Magazine - USA Edition

MAY'S WAYS— January 2017 30 that I test for potential mold problems, rather than for the absence of such problems. If you suspect that there is mold growth in a building where you live and work, and you want to hire someone to test for mold, be sure the per- son is experienced, and that mold testing is the person's major profession (and not remediation). ing's occupants' symptoms (where, when, what), always trump mold-spore air-test results. I know it's odd for me, an IAQ professional, to generally question the usefulness of air sam- pling for mold, since I do air and surface sam- pling myself. But I put more weight on surface sampling, which points the way to locations of mold growth. I tell potential clients as well as my fellow IAQ professionals that identification of the source of an IAQ problem is the goal. Taking a surface sample, therefore (a swab or tape sample) of a stain can be useful. But air sampling for mold by itself need not be undertaken in the absence of a musty smell, spots that could be mold growth, or a building occupant who is allergic to mold and is experiencing symptoms. Sometimes I won't take samples at all. If someone calls me and asks me to test for mold "to be sure there is no problem," I explain that such testing is meaningless. Mold can grow within 24 to 48 hours if moisture (spills, leaks, water intrusion, relative humidity over 80%) and a food source (dust, skin scales, spilled food, sawdust) are present. So depending on condi- tions, a basement that is mold free one week can be full of mold growth a few weeks later. Such "clearance testing" therefore does not predict fu- ture conditions. This is why I explain to clients Efflorescence on brick foundation wall May Indoor Air Investigations LLC Efflorescence on concrete foundation wall May Indoor Air Investigations LLC I worked with one client who was told by a tester from a remedia on company that her basement was so contaminated with mold that she should not be living in the house. The person quoted her a $3,000 fee to remove the mold. She promptly moved into a hotel, but called me for a second opinion. The "mold" ended up being efflorescence – crystals of cemen ous material that form on the inside of founda- on walls when moisture migrates through the concrete. That moisture can help fuel mold growth within the basement, but is not mold growth. The client could have paid $3,000 to have the efflorescence removed, but it would have reappeared because the house's gu er system was not being well maintained, so roof water was splashing up against the founda on at the exterior and migra ng through the founda on wall. Thankfully, most reputable remedia on companies recommend that a third party do the pre- and post-remedia on tes ng.

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