Water damage often hides behind finished surfaces. A thermal camera cannot see water itself, but it can show temperature patterns that point to where moisture may be.
Why moisture shows up
Wet building materials typically behave differently from dry ones. Evaporation cools damp areas, and water changes how a material stores and releases heat. A damp patch of ceiling or wall often appears cooler than the dry surface around it, or heats and cools at a different rate through the day.
Where to look
- Ceilings below bathrooms, roofs and upstairs plumbing
- Walls beside tubs, showers and washing machines
- Under sinks and around water heaters
- Exterior walls near downspouts, window corners and foundations
- Flat roofs and skylight surrounds
Technique
- Take a visible-light photo of the area for reference.
- Scan slowly from a short distance, then step back to see the pattern's shape and edges.
- Compare with a similar dry area nearby.
- Scan again later, since moisture patterns can change as a house warms or cools.
- Try the scan on a few different color palettes. See color palettes explained.
Always confirm
A cool patch is a clue, not proof. Cold bridges, missing insulation and air leaks can look similar. Confirm suspected moisture with a moisture meter or an invasive check before cutting or repairing anything. For plumbing leaks, call a qualified plumber.
Which camera?
Sensitivity matters here because moisture signatures can be subtle. Look for a low NETD and at least 256×192 resolution. See what NETD means, and browse handheld cameras.