Thermal Infrared Images Help Needed

I recently performed an IAQ inspection of a house with a site the sloped upward away from the structure thus promoting flow of rain water toward the structure. I used thermal infrared imaging to view in the interior side of the exterior wall. Several thermal anomalies were discovered along this wall is a wide range of locations. However, none of the areas with anomalies showed elevated moisture when tested with a Protimeter MMS moisture measurement meter in either destructive or non-destructive modes.

Can anyone suggest what conditions in the structure may have lead to the observed anomalies? The house is about 50 years old but very well renovated. Could this be due to cold air infiltration? The anomalies are not regular in shape or distribution.

The photos and brief description can be found at:


Jeff Deuitch
Palmetto, FL

I would really have to know more about the conditions… outdoor temps, etc… and need perhaps some measurements on scene… It looks like the one image you saved in greyscale could be the wall studs shwing through… The one below it; one section of the wall between wall studs where perhaps you may have insufficient insulation or even an exterior air leak, but since you are in florida i would expect it is probably warmer than 62 degrees outside but,then again maybe not in february. There is a chance you are letting cooler air in through the outlet cover and from the window from the inside as well… Which might explain the cold spot above the outlet in the image above the greyscale one. In the top one again you have some wall studs showing which leads me to believe that it is warmer outside and the denser 2x4 wall studs have not reached the same level of thermal energy at 1:35 in the afternoon as the less dense areas between the studs. But again without being able to be at the scene it is just a somewhat educated guess on my part.

Is the house on a crawl space or slab-on-grade?
Any exterior drainage systems?
Was this bump out facing the sun when you took the images?

My first thought (just briefly looking at it) is air infiltration at most of the areas.

Pic1 & 2: Dark/cold spots on walls at outlets,corners baseboards are MANY times related to air infiltration or lack of insulation. Areas around windows should always be looked at carefully (exterior and interior). Was there any sealant around the windows? Baseboards? Outlets?
Pic3: I see studs and nails (right side). Also, drapes should have been lifted or removed well before the photos were taken as they will block air flow, etc. and result in inaccurate info.
Pic4:Area above outlet could be moisture or air infiltration from sill or from possibly from top of outlet. Area at right side appears to be feathering up, thus air travel or moisture wicking up from below.

Of course, these are just my opinions from what i can see in the photos. I am sure you have more data to take into consideration. Good luck!

Air leaks or missing insulation in some, others are just thermal bridging at the framing.

Your protocol sounds essentially correct. Scan with IR then test for moisture. In my limited experience (with a ToughCam) there are invariably some insulation booboos, esp. around electrical boxes, top plates and corners. With high exterior temp differential and a tight display span (like 12 degrees), they are everywhere.

I don’t report them - unless the listing agent is on my *** :mrgreen:

Without lots of experience and a collection of good moisture meters, IR is shooting in the dark.

Russell in BubbaLand

Thanks for the replies. I have put up a second posting which shows some of the visible images corresponding to the thermal images. My concern is if air infiltration is occurring sufficient to allow prominent anomalies, then what would happen in summer? IN SW Florida summer air contains very high levels of water vapor with dew points approaching 80 degrees F. Of course, also in summer the interior surfaces will likely be cooled below this due to the use of A/C. Cracking of paint where the baseboard trim meets the small piece of ornate trim at floor level was observed in multiple locations with some swelling and separation present. Possible signs of moisture content?

As a microbiologist I have referred the matter to construction professionals or engineers. Destructive testing was not permitted in this project. I would be interested to see what is going on inside the wall cavity.

Thanks all, and please feel welcome to post details and interesting photos from your projects on the IAQ Forum. This is an educational process for all.