One of the most important tools we use while doing a structural inspection is a manometer or water level survey. A water level survey can give precise amounts and areas of floor sag or distress. The water level is superior to a standard four-foot level in this type of application because it shows relative elevation readings throughout the entire structure. This includes around corners and relative elevations from the front entry all the way to the rear bedroom. This information can be used to pinpoint areas in the crawlspace or basement that may have problems such as misaligned walls, damage or improper construction such as long-spanning joists.