Moisture Verification Methods for Low-Slope Roofs

Non-destructive screening can narrow the search

Capacitance, impedance, thermal, or other screening methods can identify areas that differ from surrounding roof. They are useful for targeting, but each has material and assembly limitations.

Physical verification provides stronger evidence

Cores, probes, test cuts, or other direct methods can confirm construction and moisture at a specific point. The number and location of verification points should be chosen intentionally.

Use controls and representative locations

Good verification includes suspected areas and comparison areas so the result is not biased toward only abnormal locations. Record exact coordinates or map references, depth, materials, and observed moisture.

Practical owner checklist

• Choose a method compatible with the roof assembly.
• Use screening to target verification where appropriate.
• Include comparison or control locations.
• Record construction, moisture, location, and repair of test openings.