Carl Brahe
Flooding from any source can leave hidden water damage. Fungal growth like mold and wood rot start quickly when porous surfaces are soaked to over 19% for 48 hours. Exposed surfaces like dry wall may be dry to the touch on the outside but be soaked on the back side. This can be hard to detect, but water and the materials it soaks gain and lose heat at different rates. This temperature difference transfers to the exposed surface and can be detected by infrared imaging.
Typical infrared cameras can detect differences as small as .15° F. in the temperature of most surfaces. Some surfaces, like windows, reflect IR rays so IR imaging doesn't work on these. IR imaging works well on those materials that grow mold and rot.
Flood waters can cascade behind walls or be wicked up from water on the floor. The water can be invisible to the naked eye but can be seen very clearly with IR imaging. The extent of damage can be estimated before tearing open walls. There are other things that can be mistaken for moisture in materials like missing insulation or metal framing parts. IR images should be confirmed using moisture meters.
Inexpensive pin type and pinless moisture meters are available that can be used to identify moisture in building materials. An inexpensive IR device from Black and Decker identifies temperature differences, called Delta T, using a color changing flashlight device. These tools may be used by a homeowner or handyperson to identify some hidden problems. They won’t reveal hidden moisture as well or to the extent of IR imaging but can be helpful when this option isn't available.
IR technology available to professionals and individuals can help in all phases of flood clean-up. Initial damage assessment can be enhanced to help minimize unexpected damage during the tear out phase. Drying progress can be monitored until all materials are dry. When the moisture is gone the mold and rot quit growing.
This image shows water in the drywall from a leaking toilet shutoff.