Thermal Roof Documentation for Commercial Buildings

Most owners and asset managers see their roofs only when a contractor sends photos. Aerial thermal and RGB documentation changes that by putting a dated, repeatable record of the whole roof on file.

What thermal imagery records

A thermal camera records surface temperature. It does not see water, damage or defects. As NRCA's Professional Roofing puts it, "infrared imagers do not see moisture; they see temperature differences."

Those differences have a physical cause. During the day a roof absorbs solar heat. After sunset, as the surface cools, materials that hold more heat stay warmer than the areas around them, according to IIBEC's technical journal Interface. A thermal image captured in that window shows which parts of the roof are releasing heat differently.

What that pattern means is a separate question. A warmer area could reflect a change in materials, a past repair, rooftop equipment, or a condition a roofing professional will want to investigate. The image records the pattern. It does not explain it.

RGB imagery captured on the same flight adds the visible context: the membrane surface, seams, flashings, drains, penetrations, rooftop units and any debris. Paired, the two layers let a reviewer see what is on the surface where a temperature difference appears.

Conditions that make a capture useful

Thermal roof imagery is sensitive to timing and weather. A capture under the wrong conditions can show patterns that mean nothing.

ASTM C1153-23, Standard Practice for Location of Wet Insulation in Roofing Systems Using Infrared Imaging, is the active ASTM standard for this work. Its scope covers night imaging, includes both ground-based and aerial methods, and addresses meteorological conditions, operator qualifications, and verification of infrared data with invasive test methods. It applies to roof systems with insulation above the deck in contact with the waterproofing, so not every roof is a fit.

The Infraspection Institute lists conditions for imaging low-slope roofs:

• A mostly sunny day before the capture, so the roof absorbs heat.
• A dry roof surface at sunrise, with no ice, snow, or standing water, and no rain on the day of the capture.
• Wind under 15 mph at roof level during the day and during the nighttime capture.
• Daytime highs above 40 degrees Fahrenheit.
• Capture at night, after the sunny day.

Scheduling around these conditions is part of the job. A capture that does not meet them is not a reliable record.

Why a baseline and repeat captures matter

A single capture shows the roof on one night. Its value grows when the same roof is captured again under comparable conditions and the records can be laid side by side.

IIBEC's Interface notes that a survey after a new roof is installed provides a "baseline" of the roof's condition, and that surveys repeated over the roof's life can bring small problem areas to attention within a year instead of leaving them unnoticed year after year.

Maintenance planning

NRCA recommends scheduled roof system inspections at least twice a year, preferably in spring and fall, with additional inspections after severe weather such as a hailstorm, according to Professional Roofing. The Asphalt Roofing Manufacturers Association (ARMA) recommends routine inspections in spring and fall. A dated aerial record on a similar schedule gives your roofing consultant a history to compare against, and helps you plan capital spending around documented change rather than surprises.

Warranties

ARMA warns that neglecting inspections and repairs can void a roof warranty, as can failing to notify the warrantor before installing new rooftop equipment. It advises owners to "maintain records to be sure coverage is clearly defined." A dated record of roof condition, kept alongside contractor reports, supports that file.

Insurance claims and pre-loss condition

After a storm, the question is often whether damage was caused by the event or existed before it. A coverage law blog on hail claims observes that close-up photos of roofs are rarely taken just before a hailstorm, which makes storm damage hard to separate from prior wear. An IA Magazine coverage Q&A on a commercial building describes a hail claim denied because the owner could not document a roof replacement, and points to inspection reports and photos as the way to establish baseline condition.

A dated record does not decide a claim. It gives your adjuster, broker and roofing professional evidence of condition before the loss.

Interpretation stays with roofing professionals

Thermal patterns are prompts for further investigation, not conclusions. Professional Roofing notes that ASTM C1153 requires anomalies to be verified by invasive methods: core cuts, or cores combined with moisture meter probes. That work belongs to a qualified roofing consultant or contractor who can get on the roof, take samples and decide what to do next.

How FlyCRE fits

FlyCRE flies commercial roofs on a schedule and keeps a permanent, timestamped record in four layers: orthomosaic, thermal, asset visibility and multispectral. Thermal captures are planned around weather and timing so each record is comparable to the last.

We document. Qualified professionals interpret. Your roofing consultant, warrantor and insurer get a dated condition history to work from.