Wood Destroying Organism (WDO) Home Inspection Practice Exam

Focusing on soil grade is crucial for a certified wood-destroying organism (WDO) inspector because it directly affects drainage around the structure. Proper grading ensures that water flows away from the foundation, reducing the risk of moisture accumulation. This is particularly important because excessive moisture can lead to conditions conducive to the growth of wood-destroying organisms such as termites and fungi.

Inspectors assess the slope of the soil around the home, looking for any areas where water might collect or pool. If the grade is inadequate, it can result in water infiltration into the structure's foundation or basement, leading to structural damage and providing a moist environment that encourages pests.

Other factors such as soil texture, ground cover, and temperature do play roles in moisture retention and pest activities, but they are less immediately influential on drainage and the risk of accumulation near the structure compared to soil grade. Soil texture can affect how quickly water drains, ground cover can influence evaporation rates and shading, and temperature can impact pest activity. However, soil grade is the primary concern when inspecting for moisture accumulation that may lead to pest problems.