Moisture Inspection
Inspection sequence
- Stop or control the water source before placing equipment; a live leak defeats any drying system.
- Interview occupants for when, what and how long, then inspect both sides of assemblies.
- Start non-invasive: pinless meter and thermal camera to locate anomalies, then confirm every anomaly with a pin meter or probe.
- Pin meters read moisture content in wood and wood moisture equivalent (%WME) in drywall; apply the meter's species and temperature corrections.
- Concrete surface meters are comparative only. Use ASTM F2170 in-situ RH probes at 40% of slab depth for slab decisions.
- Establish a dry standard from unaffected material of the same type and similar construction.
Map and classify
Sketch the affected area, mark readings, and note wicking heights and boundaries. Category describes water cleanliness: Category 1 sanitary, Category 2 significantly contaminated (washing-machine discharge, urine without feces), Category 3 grossly contaminated (sewage, flood water); Category 1 water standing over about 48 hours may degrade. Class 1–4 describes extent and materials affected, not cleanliness.
Worked example
A supply-line failure in a 200 ft² bedroom, found within hours. Unaffected drywall reads 8% WME. The wet wall reads 18% at the base and 12% at 14 in up; carpet and pad are saturated. This is Category 1 and Class 2: wall wicking under 24 in with carpet and cushion saturated. The dry standard is 8% WME; the goal is within about 2 points of it, not zero.
Traps
Treating pinless readings as absolute moisture content; skipping temperature and species correction; assuming a slab is dry because the surface reads low, since concrete dries from the top down; missing baseboards, sill plates and cavity moisture.