Structural provisions, foundations, and materials of construction
Domain 4 tests structural provisions, foundations, and materials. The inspector is not designing the structure, but must verify that approved design assumptions, special inspections, and material standards are followed.
Structural administration
Chapter 16 sets design loads and load combinations; Table 1607.1 gives minimum live loads. Chapter 17 requires a statement of special inspections and structural observation for specified systems. The inspector confirms that special inspectors are approved and that reports are filed.
Foundations
Chapter 18 covers soils and foundations. A geotechnical report establishes allowable bearing pressure and frost depth. Footings must extend below the frost line and at least 12 inches below undisturbed grade. Concrete footings require proper reinforcement cover and sizing per plans.
Materials
Concrete follows Chapter 19 and ACI 318; masonry follows Chapter 21 and TMS 402/602; steel follows Chapter 22 and AISC 360; wood follows Chapter 23 and the NDS. Field inspection focuses on approved plans, material identification, connections, and required tests.
Worked example
A shallow spread footing is 3 feet wide on soil with an allowable bearing pressure of 2,000 psf. The allowable load is 3 ft × 2,000 psf = 6,000 pounds per linear foot. If the plans show a larger load, the inspector should reject the footing or require a revised design. The footing also must bear below frost depth and on undisturbed soil.
Traps
Using a generic live load instead of the occupancy-specific value; missing special inspection for high-strength bolting or welding; accepting concrete without verifying specified compressive strength; ignoring foundation drainage.