If you've been working on old buildings any length of time you know how difficult it can be to determine the extent of damage until you open things up. In the past, when I worked full time as a tradesman, I know I found it difficult to anticipate hidden problems. Now, I'm working as a preservation consultant, and my clients expect me to determine hidden conditions without damaging the building. I've found some neat tools that help me identify problems quickly and with a minimum of damage. These tools aren't found in the carpenter's toolbox. But some are inexpensive or useful enough that you might find them helpful on your projects. The tools that make up my "house detective" kit
