A thermal camera is often one of the first tools the author pulls out first to scan a site for possible hidden moisture. Dark areas on the image indicate cool areas—places that may be wet and need further investigation.

Several years ago, when I was contracting in California, a big part of my business was installing windows. At one point, a manufacturer representative told me that the manufacturer would void the warranty on windows in the 5- to 6-foot range if there were fasteners directly nailed through the mounting flange at the header. This warranty requirement existed because most header stock on the West Coast at that time was full-dimension, green stock. It was so heavy with water, you could be splashed when you cut into it with a saw. Understandably, window makers were concerned about what would happen to the flange fasteners as those big, wet headers dried out and shrank. The solution, the rep told me, was be sure to install fasteners into header stock that measured below 15% moisture content. If I could document that, the installation could be warranted. But at the time, I had no idea how to measure lumber moisture content.

Learning about measuring moisture content started me down a path that led to my acquiring a Pelican case full of diagnostic tools, most of which are designed to measure moisture in one form or another within building materials and in the environment inside or outside buildings. These days, I live and work in New Orleans. I was drawn here shortly after Hurricane Katrina devastated large swaths of the city, and I saw how I could be useful in helping to rebuild the 9th Ward, which was particularly devastated by floods from Katrina and subsequent storms. For this work, and for ongoing work here in this hot, humid climate, reading moisture is a big part of defining effective building solutions.

In this article, I will “unpack” my case. Not only do the tools within allow me to derive quantifiable moisture measurements, but just as important, many of them streamline how I document the problems I encounter, which helps me communicate the solutions I come up with to clients and subcontractors. Data is every­thing. I have learned that to be convincing and to educate clients, it is essential to have tools that will quantify environmental conditions, including, but not limited to, wood and drywall moisture content (MC), relative humidity (RH), temperature, and observable (that is, graphic) conditions.

Read More