Blog · Thermal · November 2026

Thermal roof imaging: what it finds, how it works, and what we deliver

A roof can look perfect from above and still be holding water underneath. Wet insulation under a flat or low-slope roof stays warm after sunset, and a thermal camera can see that warmth across the whole roof in one flight, without cutting a single core.

What it's used for

• Before a re-roof. Most commercial re-roofs only need the wet insulation replaced. A moisture map shows which areas are wet and which are dry, so the dry insulation can stay and the roof can be recovered rather than torn off.
• Tracking down a leak. Water often travels a long way under a membrane before it drips inside. A thermal survey shows where the wet area actually is, which narrows down where to look for the way in.
• Buying or managing a building. Property managers, HOAs and buyers use it as a condition check before a purchase, at the end of a warranty, or as a yearly baseline to compare against.
• After a storm. Hurricane damage isn't always visible. A survey after a storm shows whether water got in, and gives a dated record for a claim.

Thermal cameras have other uses on a building, such as spotting solar panels that run hotter than the rest of an array. This article is about roof moisture, which is the work we do.

How it works

Everything gives off infrared energy, and the warmer it is, the more it gives off. A thermal camera measures that energy instead of visible light. A radiometric thermal camera goes a step further and records a temperature for every pixel, so any point in the picture can be read later.

Moisture shows up because of how roofs heat and cool. On a sunny day the whole roof warms up. After sunset it starts losing that heat to the night sky. Dry insulation holds very little heat, so dry areas cool quickly. Wet insulation holds much more, because water stores far more heat than foam or fibreboard, so wet areas stay warm for hours. Flown at the right time, the wet areas show up as warm patches against a cooler roof.

When it works, and when it doesn't

Thermal moisture surveys are dependable when the conditions and the roof are right, and misleading when they aren't. We'd rather tell you before we fly than after.

• Best on flat and low-slope roofs with insulation right under the membrane: TPO, EPDM, PVC, modified bitumen and built-up roofs, the kind on most commercial buildings, condos and churches.
• Much less reliable on shingle or tile roofs over a ventilated attic, which is most Florida homes. The airflow under the deck evens out the temperatures, so a wet spot rarely stands out clearly.
• The weather matters. It needs a clear, sunny day to load the roof with heat, then a calm, dry evening. Rain on the surface, heavy dew or a strong wind hides the pattern. We fly after dark, under the FAA's rules for night operations, and move the date when the conditions aren't there.
• Not everything warm is wet. Vents, HVAC units, skylight curbs, a patch of different roofing, or an area that caught afternoon sun while the rest was shaded can all look warm. Reading the picture well means knowing what's on the roof.

What a CAVU Aerial thermal survey includes

We fly the roof with a radiometric thermal drone and deliver everything in your own online portal, alongside any photos, maps and roof reports from the same job.

1. Thermal photos you can measure. Open any thermal photo and point at it to read the temperature, click to keep readings and see how much warmer one spot is than another, switch colour scales, and choose °F or °C.
2. A thermal map of the whole roof. The thermal photos are stitched into one map, so you see the entire roof at once instead of photo by photo. It can be laid over a colour map of the same property, with a slider to fade between them, and read at any point.
3. A moisture survey in your roof report. On each slope of the roof, we outline every area warmer than the rest of that slope, with its size in square feet and how much warmer it is. Comparing each area with its own slope, rather than relying on one absolute temperature, makes the result much less sensitive to the camera's own error and to the weather on the night.
4. Reviewed by us before you see it. The software finds the warm areas; we check every one, take out what's clearly a vent, a curb or a patch, and record the flight conditions: when we flew, the air temperature, wind, sky and the last rain. You see the survey once we release it.
5. Files for your roofer and your records. A thermal picture of the whole site, the temperature map as a GeoTIFF for GIS, and a report you can print or save as a PDF.

If you also book a roof report, the moisture survey sits in the same report as the slopes, pitches, squares and edge lengths, so a roofer can price the repair from one document. Our sample roof report shows the layout, with an illustrated finding rather than a real survey.

Booking a thermal survey

Tell us about the building when you book: the roof type, roughly how big it is, and what you're trying to find out. We'll check whether thermal is the right tool for that roof, pick an evening with the right weather, and let you know if the forecast moves the date. For a home with a shingle or tile roof, we'll usually suggest a roof report and close-up photos instead, because thermal is unlikely to give you a clear answer there.