An infrared thermal imaging inspection form is the record that makes a thermal scan worth trusting: the conditions on the day, the camera and how it was set, the areas scanned, and every anomaly with its temperature difference, a thermal image beside an ordinary photo, and whether a moisture meter or another tool confirmed what the camera suggested. This one is written for home inspectors, and you can fill it in here and download a PDF without an account.
A thermal image shows temperature, nothing else
An infrared camera measures the heat coming off a surface. It does not see through drywall, into a wall cavity or behind tile. A cool patch on a ceiling might be wet drywall, missing insulation, an air leak or a cold duct above it; a warm patch might be a hot water line, a bad connection or just afternoon sun on the other side of the wall.
That is why every anomaly in this form asks for a second check. A moisture meter reading, a look in the attic or a touch of the breaker with a non-contact thermometer turns a pattern into a finding. Until then, report it as an anomaly that needs confirming.
Conditions decide what you can find
Insulation and air-leakage patterns only show when heat is moving through the walls. A common rule of thumb is a difference of about 18°F (10°C) or more between inside and outside, held for several hours before the scan. In mild weather you can create some of that with the heating or air conditioning, or reveal air leaks by depressurizing the house with a blower door or exhaust fans.
Sun on a wall can swamp everything for hours afterwards, wind cools exterior surfaces unevenly, and rain leaves the outside of the house wet and cold. Recording these lets a reader judge whether a clean scan means a clean house or simply the wrong day.
Settings that make images comparable
Most painted and unpainted building materials have an emissivity of roughly 0.90 to 0.95, but shiny metal, glass and glazed tile reflect heat from elsewhere and read falsely. Note the emissivity and reflected temperature you used, and set the level and span tightly enough that a few degrees of difference shows up.
Save radiometric images where your camera allows it, so temperatures can be checked later. Pair each thermal image with a visual photo from the same spot — a client cannot locate a purple blob on a white ceiling without it.
Electrical scans need care
A hot breaker or lug is worth reporting as a safety concern, but panels should be scanned under normal load and only opened by someone qualified to do so. If the cover stays on, say so: a scan through a closed cover sees the cover. Refer any electrical hot spot to a licensed electrician rather than diagnosing the cause.
Common questions
Can a thermal camera see moisture inside walls?
Not directly. It sees surface temperature. Wet materials are often cooler because water evaporates from them, so moisture can show up as a cool pattern, but so can several other things. Confirm each suspected wet area with a moisture meter before reporting it as moisture.
What temperature difference do I need for an infrared scan?
For insulation and air-leakage work, a commonly used rule of thumb is about 18°F (10°C) between indoors and outdoors, held for a few hours. Moisture and electrical scans depend less on the outdoor temperature. Record the actual temperatures so the reader can judge.
Should every thermal image go in the report?
Only the ones that show something, plus enough normal images to show the areas were scanned. Each reported anomaly should have its thermal image, a matching visual photo, a location, the temperature difference and what was done to confirm it.
Is a thermal scan part of a standard home inspection?
Usually not. Most home inspection standards do not require infrared, and many inspectors offer it as an add-on. When it is included, the report should say what was scanned, under what conditions, and what the scan cannot show.
Do I need a certification to offer thermal imaging?
Training is strongly advised, because misreading an image is easy and clients take thermal images as proof. Some states and insurers also expect a certification. Check what applies where you work and what your errors and omissions insurer requires.