Roof moisture inspections are one of those applications of infrared thermography that many in the industry have heard of, but not so many have attempted. It’s kind of a niche application, really. In my decade or so of experience in this industry, I’ve only had the opportunity to be involved in a handful of these types of inspections. Each one was unique, and each presented its own set of challenges.
The ASTM C1153, Standard Practice for Location of Wet Insulation in Roofing Systems Using Infrared Imaging is the guiding document for these types of inspections. It lists the conditions that have to be met in order for an attempt at a roof moisture inspection to be successful. Roof moisture inspections are really as much an art as they are a science. The standards suggest beginning your inspection an hour or two after sunset, after a sunny day. How long precisely it takes for a pattern to emerge is dependent upon many factors. Roof construction, weather conditions, camera resolution, lots of things. There’s no hard, fast rule. If there’s ballast on the roof, that impacts both what you see as well as how soon you see it. Also, the patterns often can be obscure, so it takes an experienced eye to pick out some of the lower magnitude anomalies.
What does the newly minted thermographer do then? It’s a good idea to spend some time perfecting the inspection process. If you can, try to tag along with a more experienced thermographer on your first few roof inspections. That’s a good idea with any of the applications really. Try to keep in mind that mastering an art takes time and give yourself plenty of opportunity to practice.
Think Thermally, www.thesnellgroup.com The Snell Group, a Fluke Thermal Imaging Blog content partner