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National Association of Infrared Specialists
USA

16192 Coastal Highway, Lewes, Delaware 19958

CANADA

NAIS Commercial Roofing Standards of Practice (RoofSOP)

This standard sets the requirements for infrared surveys that locate wet insulation in flat and low-slope commercial roofing systems.

Section 1: Purpose, Scope and Alignment

1.1 Purpose. To set a uniform, defensible minimum standard for infrared roof moisture surveys.

1.2 Alignment with NAIS Core Standards. This standard is an addendum to the NAIS Core Standards of Practice (CoreSOP) and the NAIS Code of Ethics. Everything in the CoreSOP applies unless this standard says otherwise. It is based on ASTM C1153 (location of wet insulation in roofing systems using infrared imaging).

1.3 Scope. Non-invasive evaluation of accessible flat and low-slope roof surfaces to locate areas of suspected wet insulation.

1.4 Exclusions. This standard does not cover roof condition or warranty evaluation, leak-source identification beyond suspected moisture, structural evaluation, or the design of repairs.

Section 2: Principle

During the day, solar gain heats the roof. After sunset, wet insulation holds heat longer than dry insulation, so wet areas appear warmer than dry areas on the thermogram.

Section 3: Required Conditions

  1. The survey shall be done from 1 to 4 hours after sunset on a clear night with low wind.
  2. The roof shall have been dry through the preceding daytime, and the surface shall be dry during the survey.
  3. Daytime sun shall have been strong enough to heat the roof. When the weather did not allow this, the report shall say so and state the effect on the result.
  4. Roof access shall be safe and agreed in advance (CoreSOP Section 6.2).

Section 4: Procedure

  1. Survey the roof in a grid or marked lanes, and mark every anomaly on the roof surface with a removable marker so it can be matched to the plan.
  2. Separate moisture patterns from other causes of warm areas, such as patched or thicker areas, ballast, equipment, drains and the age of the roof.
  3. Include a roof plan marked with the anomaly outlines in the report.

Section 5: Verification

All anomalies suggesting wet insulation shall be verified by core samples, moisture meters, a nuclear gauge or another invasive or direct method before the thermographer recommends roof replacement or repair. The report shall record each core location and result, and openings shall be repaired by a qualified roofer.

Section 6: Reporting

The report shall meet CoreSOP Section 7, with the following added: the time after sunset, sky and wind conditions; a roof plan showing the anomaly outlines and core locations; and the roof type and apparent age.

Section 7: Limitations

This survey locates thermal patterns consistent with wet insulation. It does not show the cause of a leak or the condition of the membrane, and it cannot be done in rain, in snow or on a wet or snow-covered roof. The CoreSOP limitations statement shall appear in every report.

© 2026 National Association of Infrared Specialists (NAIS). Permission to copy, reference, or commercially cite this standard in infrared thermography reports or contractual agreements is granted exclusively to active NAIS members in good standing.