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: http://www.iaqforum.net/showthread.php?p=227#post227

Thanks.

Jeff Deuitch
Palmetto, FL

Do we know what type of insulation was used and when it was installed? I am no expert, but my first thought was that possibly the extreme changes in moisture levels within the wall have caused compression and deterioration of the insulating material. My coastal bred mind also worried about the high probability of mold within the wall.
While I understand that you can't do any boring, you should be able to pull those outlets and explore the walls more thoroughly without damaging anything.
If the seller refuses to allow that alternative, I would have a hard time advising my client to go forward with the purchase...even if those floors are beautiful beyond belief.

The moisture may be seasonal and it may have damaged the insulation in those areas. The areas around the electrical sockets are normal and not in any way abnormal. The areas under the windows suggest water infiltration to some extent in a normal pattern - to me anyway.

I am not familiar with this technique but if asked to look at the pictures without hearing you say they were abnormal, I would say that it looks as expected for a slab on grade home. Around windows, at electrical and radiating up from the slab would be spots I'd expect to see some deficiencies.