Moisture Probe Test vs Thermal Imaging

Many people are horrified by the thought of drilling holes through the stucco facade of their home.  This leads them to pursue other avenues such as thermal imaging to determine the health of their stucco.

The truth is, the holes required for a probe test are tiny inconspicuous specs when all is said and done.  The holes are required to access the substrate (sheathing) and framing behind the stucco to determine the overall health of the structure.  After the test is carried out, the tiny holes are filled with a colored caulk product and all but disappear from view, leaving the home in the same physical and aesthetic shape it was in prior to the test. This form of testing is extremely effective in discovering bad (or good) framing and sheathing, and gives a very good overall picture of the success or failure of the applied stucco.

Thermal imaging on the other hand does not require penetration of the stucco facade, but it has serious limitations.  Thermal imaging cameras see only heat, and can see very slight differences in the temperature of any surface it is pointed at.  The key word here is “surface”.  Contrary to popular belief, thermal cameras CANNOT see through a wall, they simply depict the temperature of the first layer they at looking at.  They cannot see if any moisture is behind the stucco.

In perfect conditions, a thermal camera may see a slight temperature difference caused by moisture sitting behind the stucco, and as water conducts heat 4 times better than air, it is feasible that this could be detected.  This scenario is extreme and highly unlikely to be successful in the majority of cases.  More likely to be seen is the uneven heating of the stucco from the sun light or just the ambient air temperature changing throughout the day.

Probe testing is the only effective way to inspect stucco for failure.  Don’t pay for an expensive thermal inspection that will likely produce false results.