OWNER BUILDER EXAM PREP QUESTIONS COMPLETE WITH 100% VERIFIED ANSWERS

OWNER BUILDER EXAM PREP QUESTIONS COMPLETE WITH 100% VERIFIED ANSWERS 1. According to OSHA regulations, at what depth of trench is shoring required? A) 3 feet B) 4 feet (1.2 meters) C) 5 feet D) 6 feet Correct Answer: B) 4 feet (1.2 meters) Rationale: OSHA requires that any excavation 4 feet or deeper must have protective systems in place. This is a fundamental safety regulation to prevent cave-ins and protect workers. The 4-foot threshold is specifically mandated for trenches where workers may enter. ________________________________________ 2. Which of the following is NOT an acceptable method for determining the correct grading for a trench? A) Written specifications from a qualified registered professional B) Following angles shown in Figure 20-1 based on soil conditions C) Experienced contractor says it's acceptable D) Benching as shown in Figure 20-2 Correct Answer: C) Experienced contractor says it's acceptable Rationale: Oral approval from an experienced contractor is never sufficient for determining trench grading. All grading must be documented, engineered, or follow specific regulatory figures. Verbal assurances do not meet safety standards. ________________________________________ 3. How can shoring be done past 4 feet depth? A) Only with steel beams B) With purpose-built shoring or properly constructed plywood C) Only with aluminum hydraulic shoring D) By benching the sides Correct Answer: B) With purpose-built shoring or properly constructed plywood Rationale: Both purpose-built shoring systems and properly constructed plywood are acceptable methods for shoring excavations deeper than 4 feet. The key requirement is that the system must be properly engineered and constructed to withstand soil pressures. ________________________________________ 4. Before a worker enters any excavation over 1.2 m deep, what must the employer ensure regarding the sides? A) They are visually inspected daily B) They are sloped as specified in writing by a qualified registered professional C) They are covered with tarpaulin D) They are watered down to prevent dust Correct Answer: B) They are sloped as specified in writing by a qualified registered professional Rationale: The regulations explicitly require written specifications from a qualified registered professional for sloping. This ensures engineering oversight and creates documentation for safety compliance. ________________________________________ 5. In no case may the slope or combination of vertical cut and slope exceed what? A) Figure 20-1 B) Figure 20-2 C) Figure 20-3 D) Figure 20-4 Correct Answer: A) Figure 20-1 Rationale: Figure 20-1 provides the maximum allowable slopes based on soil conditions. Exceeding these limits creates unacceptable risk of cave-in. This figure establishes the absolute maximum safe angles. ________________________________________ 6. What is the minimum depth requiring protective systems for excavations? A) 2 feet B) 3 feet C) 4 feet D) 5 feet Correct Answer: C) 4 feet Rationale: Four feet (1.2 meters) is the threshold depth at which protective systems become mandatory. This is based on fatality statistics showing cave-ins become significantly more dangerous at this depth. ________________________________________ 7. Which of the following is an acceptable method of supporting excavation sides? A) Supported as specified in writing by a professional engineer B) Supported by verbal agreement with supervisor C) Supported by wire mesh only D) Supported by tree trunks Correct Answer: A) Supported as specified in writing by a professional engineer Rationale: Professional engineering specifications are required for support systems. Verbal agreements and improvised materials without engineering approval do not meet safety requirements. ________________________________________ 8. What does section 20.85 address? A) Minimum requirements for trench supports B) Maximum depth of trenches C) Soil classification methods D) Equipment operation near trenches Correct Answer: A) Minimum requirements for trench supports