CPI CPI Site Preparation & Layout Planning 1 — Questions and Answers
Question 1: Before beginning excavation on a job site in the US, which free service must an installer call to locate underground utilities?
- Local fire department
- 811 (Call Before You Dig) (Correct answer)
- OSHA hotline (1-800-321-OSHA)
- Local building department
Correct answer: 811 (Call Before You Dig)
Dialing 811 connects you to the national 'Call Before You Dig' service, which notifies all underground utility owners who then mark lines within 2–3 business days before excavation begins.
Question 2: What is the purpose of a site plan benchmark during a construction layout?
- It marks the location of underground hazards
- It establishes a fixed reference elevation for all vertical measurements (Correct answer)
- It designates the area for material storage
- It identifies the property corners for legal surveys
Correct answer: It establishes a fixed reference elevation for all vertical measurements
A benchmark is a permanent, known-elevation reference point from which all vertical measurements on a site are derived to ensure consistent and accurate grade control.
Question 3: When establishing building layout lines with batter boards, what is the correct sequence?
- Set batter boards, drive corner stakes, pull string lines
- Drive corner stakes, set batter boards outside corners, attach string lines (Correct answer)
- Pull string lines first, then anchor with corner stakes
- Pour footings first, then set batter boards for superstructure layout
Correct answer: Drive corner stakes, set batter boards outside corners, attach string lines
Corner stakes locate the building corners, batter boards are then set back from corners to allow excavation without disturbing layout, and string lines are strung between boards to re-establish corners as needed.
Question 4: Which method is used on-site to verify that a layout corner is square (90°)?
- 3-4-5 rule (Pythagorean triangle)
- Using a standard carpenter's square only
- Measuring equal diagonals only
- Both A and C (Correct answer)
Correct answer: Both A and C
Both the 3-4-5 (or 6-8-10) triangle method and the equal-diagonal check are used together to confirm a true 90° corner during building layout.
Question 5: What does the term 'finish grade' refer to on a site plan?
- The quality rating of the topsoil to be imported
- The final planned elevation of the ground surface after grading is complete (Correct answer)
- The slope of interior finished floors
- The grade of aggregate used under foundations
Correct answer: The final planned elevation of the ground surface after grading is complete
Finish grade is the final elevation of the ground surface around a structure after all grading, filling, and landscaping work has been completed according to the site plan.
Question 6: What minimum slope away from a structure is generally required by residential building codes for positive drainage?
- 1% (1/8 inch per foot) for at least 6 feet
- 2% (1/4 inch per foot) for at least 6 feet (Correct answer)
- 5% (1/2 inch per foot) for at least 10 feet
- 10% (1 inch per foot) for at least 3 feet
Correct answer: 2% (1/4 inch per foot) for at least 6 feet
Most residential codes require the grade to slope away from the foundation at a minimum of 2% (about 1/4 inch per foot) for at least 6 feet to direct surface water away from the structure.
CPI CPI Site Preparation & Layout Planning 1
Before beginning excavation on a job site in the US, which free service must an installer call to locate underground utilities?