Would thermal imaging help with this situation?

I am wondering if having this situation examined with a thermal imaging device would help detect the progress of the drying process. Here is what happened:

  • The shower pan overflowed on the second floor of a home, a one time, sudden event. Yes, this was during a home inspection, my fault.
  • Water leaked down through the floor of the bathroom, through the ceiling into the Kitchen area below.
  • Water also traveled through the exterior wall of the Kitchen, traveling between the sheetrock and the plastic vapor barrier in the wall. A little water made it to the Basement.
  • Using a moisture meter, the plywood subfloor in the bathroom is wet, the sheetrock Kitchen ceiling is wet, and the sheetrock on the exterior wall above the cabinetry of the Kitchen is wet.
  • Servpro was brought in within hours of the event and set up fans, injector blower unit, and dehumidifiers.
  • We are monitoring the drying and it is measurably improving.
  • The question is whether we will need to remove Kitchen cabinets to ensure that the area between the sheetrock and the vapor barrier is drying properly, or if moisture is trapped in there and must be opened up to facilitate drying.

Okay, so this is my question regarding the use of a thermal imaging device:

  • Would a thermal camera help determine a temperature difference between the wet and dry areas of the sheetrock that is behind the Kitchen cabinets and tile backspash?
  • The water event happened about 2 days ago, so the temperature of the water will probably be the same as the drywall.
  • Fans are blowing on the area, an industrial dehumidifier is running in the Kitchen, and the inside temperature has been turned up to about 71 degrees for the last 2 days. The temperature outside has been a steady 40 degrees the entire time.
  • From my limited understanding of interpreting thermal images, it seems to me like a thermal image would not help with this situation since the dry sheetrock and the damp sheetrock would be very similar, if not exactly the same, in temperature.

Any thoughts on this besides don’t leave a shower running unattended, ever?


Can’t help with the thermal Q but that is a tough way to learn a lesson.
Hope you have E&O


Why, was the drain clogged?

I have a IR and it works great detecting minute moisture. Around toilets and under sinks.
It’s not just for heat loss. In fact, it shows your foot print on carpeting. Or you impression on furniture.

1 Like

-It won’t see through cabinets at all. If the back wall of the cabinet is a different temp, maybe it will show up if the device is tuned properly.
-Scanning the drywall behind wall tile is highly problematic, likely won’t yield any meaningful results.
-It never sees wet or dry directly, only temperature differences, and only on the surface of what you scan.

1 Like

If evaporation is occuring, the wet and dry areas will not be the same temperature. However, there will be little to no air movement behind the cabinets and the sheetrock. Infrared is only going to show you surface temperatures. You can’t accurately conclude by thermal imaging that the area behind the cabinet is not wet via indirect reading.

I would use a deep wall probe from the other side or drill discrete holes through the cabinet backs to check.


Yes, the drain was clogged…with my stopper

Thanks Chuck, I think that will be the best approach.

Thanks everyone, day 3 and the moisture levels have come way down, so this might not end too badly…


Condolences on the misadventure.

1 Like

To clarify your perception of Thermal Imaging…

Yes it will. But for starters you will need a “real” thermal imager.

  1. Cabinets are not in contact with the wall so the temp differential will be very slight. You will be looking for convection not conduction.
  2. Contrary to opinions here, you can detect moisture behind tile. You can not turn on your i phone thermal imager in the auto mode and just look around for it. You need to create a test condition where the temperature is in transition, not stable. Moisture changes temperature slower than dry material. Moisture changes density of a material. Moisture increases conduction of a material. Proper setup of testing will give you the Delta T you require.

This is impossible. Look up evaporative cooling. Evaporative cooling is to cold as Solar radiation is to hot. Even if you add warm airflow to the wall, the wet area will cool down before it heats up. The dry wall will just heat up.

Here you have it. Your adding heat with forced convection. Depending on the wet bulb temperature you will have a significant temperature differential present. A long as you properly adjust your camera, you’ll see it (even through the tile).

As stated above, this assumption is as far from correct as you can get. You loose 970 btu/lbs moisture without a temperature change. The thermal camera does not measure temperature (or moisture, as pointed out by others). Temperature is calculated by the camera, not measured. The camera measures energy radiation, not temperature change. It takes a change in energy to change temperature (once you overcome latent heat of evaporation). That is what makes the imager so effective. You can measure the energy even when there is no temperature change.

As Chuck pointed out, there are better tools for doing what you need without the complexities of thermal imaging. Though you can do this with thermal imaging, other tools work just as well, if not better.

What David said. My camera wasn’t cheap and neither was the training but he is spot on.

I would say that IR imaging would show if “evaporation” is taking place, because that is actually what you are seeing when looking for moisture. Thermal Imaging is only as good as the person operating it. A cheap thermal camera is of much more worth in the hands of an experienced (not just trained in a class) operator than an all the bells and whistles ($8,000) IR Imager in the hands of a novice. A Novice is going to see an ‘ocean’ of things that are not really there and get themselves in trouble. It is also why we should confirm the suspected presence of moisture with a meter.

Jon that is an incident that makes me feel sick, I would not wish that accident on anyone. I know overall it is your own doing but was the client talking your ear off with questions? I can’t stand it the other day I was looking over a water heater and the client asks me some off the wall question about the framing in the basement, I told him “right now you need to let me focus on this water heater.” As nice as I could but I was pretty annoyed


Thanks for everyone’s input! We are at day 4 and all the affected areas are measuring dry without any more invasive measures like removing cabinetry. Not cheap, but very fortunate. Lesson learned…

I don’t test with a stopper, ever, but a lotta guys do. If you’re going to continue testing with a stopper, you might consider getting one of these.


As Stephen said get the shower pan test plug. I have two of them. As an added benefit the water collected in the pan before it starts draining adds weight to the shower pan, many times they don’t leak until someone stands on them during a shower. ( a cubic foot of water weighs slightly more than 62 lbs.)

A quality thermal imager makes a huge difference. :smile:

These are easy and cheap to make your own with a Walmart flapper style drain stopper and a 1-1/2 inch piece of PVC tailpiece. Hurts less when you leave one behind and won’t overflow the shower pan.

'Course if you leave it behind you probably left the water running also…:laughing:

1 Like