Mold and Microbial Assessment
What this domain tests
Mold and microbial assessment tests whether you can investigate moisture and microbial conditions, choose sampling only when it answers a question, and produce defensible data. The assessor's first product is a hypothesis about water sources and pathways, not a spore count.
Core rules
- Start with interview, visual inspection, and moisture mapping: RH, dew point, pin/pinless meters, IR thermography, borescope. Confirm with direct moisture readings.
- Sample when needed to verify hidden growth, compare rooms, or document pre-remediation conditions. Air sampling alone cannot locate a source.
- Use outdoor control samples when interpreting airborne spores; results are site-specific and weather-dependent.
- Surface sampling methods include tape lift for visible growth, swabs for irregular surfaces, and bulk sampling for materials. Each has different recovery and interpretation limits.
- Use accredited labs, chain-of-custody, and report methods, detection limits, and uncertainties. No numeric mold-free standard exists.
Worked example
A basement smells musty, but no mold is visible. RH is 65%, and a pin meter reads elevated on drywall below a window. Reasoning: the moisture reading and dew point suggest condensation or a hidden leak. A borescope finds growth on the back of drywall. Air samples from the basement and outdoors document spores, but the finding is the moisture defect and hidden growth, not the sample alone. The report recommends source repair, further investigation, and remediation if confirmed.
Traps
- Sampling first and skipping moisture investigation.
- Calling any dark growth toxic black mold without identification.
- Using one indoor sample with no outdoor comparison.
- Treating a non-viable spore count as a health diagnosis.
- Failing to document moisture, weather, and sampling locations.