National Home Inspector Practice Exam

While inspecting a crawl space, you should probe for decay if the _________ is dark in appearance.

1. King joist

2. Floor joist

3. Masonry wall

4. Bearing wall

The correct answer is: Floor joist

Probing for decay in a crawl space is particularly relevant for floor joists, as these structural components are directly affected by moisture, pests, and environmental conditions that can lead to deterioration. If the floor joist appears dark, it typically indicates a potential moisture issue, which can cause wood decay such as rot or fungal growth. Floor joists are critical in supporting the flooring above and help distribute loads. They are also often in contact with or near the ground, making them more susceptible to moisture infiltration and, therefore, decay. Inspecting a darkened floor joist through probing allows an inspector to determine the extent of any damage, assess the structural integrity, and recommend any necessary remediation. In contrast, probing other structures such as king joists, masonry walls, or bearing walls might not be as critical or indicative of moisture and decay issues specific to the flooring system. While these components also require attention during inspections, the direct relationship of floor joists to potential decay problems makes them the most relevant option in this scenario.