InterNACHI Mold Inspector study plan

Diagram the mold growth equation (moisture, food source, temperature, oxygen, pH) and label which variables an inspector can control or document

Distinguish xerophilic, mesophilic, and hydrophilic fungi by water activity (aw) thresholds and list two indoor indicator genera for each group

Explain the difference between condensation, bulk water intrusion, and high indoor humidity as drivers of amplification, with one building example each

Identify the dew point conditions that produce surface condensation on cold interior surfaces and describe how thermal bridging creates them

Trace the six common moisture pathways (roof, envelope, plumbing, groundwater, interior vapor, HVAC) and name the diagnostic clue for each

Explain vapor retarder placement principles for cold and warm climates and describe the failure mode when placement is wrong

Describe how air leakage, not diffusion, dominates winter interstitial wetting and how to recognize the signs during an inspection

Outline the correct use of a moisture meter, pin versus pinless, and an infrared camera to confirm suspected moisture without causing damage

Build a room-by-room exterior and interior walkthrough sequence that consistently surfaces water staining, efflorescence, and microbial growth

Write the interview questions you will ask occupants about leaks, prior flooding, HVAC changes, and recent renovation

List the conditions that must be documented before sampling: visible growth area, substrate, moisture readings, and HVAC status

Explain when sampling is unnecessary or counterproductive and how to explain that to a client

Compare air sampling methods (spore trap, culturable, PCR-based) by what each detects and what each cannot detect

Describe correct cassette placement: height, duration, flow rate, and number of samples for a typical residential project

Explain the role of outdoor control samples and non-suspect indoor baselines in interpreting results

List the personal protective equipment and containment practices required before disturbing suspect growth

Read a spore trap lab report and interpret raw counts, counts per cubic meter, and the ratio of indoor to outdoor taxa

Distinguish genera that indicate water damage from genera that are common in house dust, and explain why a single elevated genus is rarely conclusive

Summarize what is well established about mold exposure and health outcomes versus what remains uncertain, without overstating either

Describe how to communicate findings to sensitive occupants, including those with asthma or immune compromise, without diagnosing

Draft occupant communication language for confirmed growth, suspected growth, and no-finding scenarios

Explain the difference between remediation and restoration and who is qualified to perform each

Describe the conditions that define a successful remediation: source corrected, growth removed, area dry, and clearance criteria met

Outline the elements of a clearance assessment, including visual inspection, moisture verification, and when post-remediation sampling adds value

Structure an inspection report with scope, methodology, observations, lab data, interpretation, limitations, and recommendations in a defensible order

Write limitation and disclaimer language that accurately reflects what a visual inspection and air sampling can and cannot prove

Review sample reports for common errors: conclusions unsupported by data, genus-level overreach, and missing moisture context

Describe record retention, chain of custody, and photo documentation practices that support the report

Complete timed practice sets weighted to domains 1 through 4 and log every missed item by domain and error type

Re-teach the three weakest concepts from memory in writing, then verify against your notes

Recite the growth-requirements, moisture-pathway, sampling-method, and clearance frameworks without notes

Review all limitations and communication language one final time to confirm accuracy and no overstatement