Thermal Drone Inspection: Complete Guide for Property Owners

Thermal drone inspection uses infrared cameras to see temperature differences across building surfaces. Cold spots indicate heat loss. Warm spots on a roof after rain indicate trapped moisture. Overheating electrical connections show as bright hotspots.

For property owners, thermal inspection answers questions that visual inspection cannot. Is the insulation working? Is water getting into the roof structure? Are there hidden electrical issues?

What Thermal Imaging Detects

Moisture Ingress

Water trapped in roof insulation or wall cavities retains heat differently than dry materials. After sunset, wet areas cool more slowly and appear as warm patches on thermal images. This is the most reliable non-destructive method for finding roof leaks without opening up the structure.

Insulation Defects

Missing or compressed insulation shows as cold patches on external walls during winter, or warm patches during summer. Thermal imaging identifies exactly where insulation is absent, damaged, or incorrectly installed.

Air Leakage

Gaps around windows, doors, and penetrations allow conditioned air to escape. Thermal imaging during pressurisation testing (blower door test) makes these leaks clearly visible.

Electrical Faults

Overloaded circuits, loose connections, and failing components generate excess heat. A thermal scan of switchboards and distribution panels identifies faults before they cause outages or fires. On solar arrays, thermal imaging detects faulty cells, failed bypass diodes, and hot junction boxes.

How the Inspection Works

A radiometric thermal camera is mounted on a commercial drone. Unlike simple thermal viewers, radiometric cameras record the actual temperature at each pixel, not just a colour gradient. This allows the analyst to measure temperature differences precisely.

The drone flies systematic passes over the building, capturing overlapping thermal images. For roof inspections, the flight is typically at 15 to 25 metres altitude. For facades, the drone flies alongside the building at each level.

Best results require a temperature differential of at least 10 degrees between inside and outside, or thermal imaging shortly after sunset when wet areas retain heat. Wind above 15 km/h reduces thermal contrast.

The Report

A thermal inspection report includes both visual and thermal images of every anomaly found. Each anomaly is classified by type (moisture, insulation, electrical, other) and severity (monitor, schedule repair, urgent).

Temperature readings are included for each finding, along with a comparison to normal operating range. The report typically includes an annotated roof plan or facade elevation showing defect locations.

Cost

• Residential thermal inspection: $400 to $700
• Commercial building: $600 to $1,500
• Solar array thermal scan: $400 to $1,200
• Industrial facility: $1,000 to $3,000

These prices include the flight, thermal imaging, and a written report with findings and recommendations.

When to Book

Schedule thermal inspections in the cooler months (May to August) for best insulation and air leakage detection. Roof moisture scans work best in the first two hours after sunset following a warm day. Solar panel inspections need clear skies with irradiance above 500 W/m2, so summer is ideal.

Post-storm inspections can be done any time. The goal is to find damage, not measure thermal performance, so weather conditions are less critical.