CFI Estimating, Layout & Planning 2 — Questions and Answers
Question 1: When estimating carpet for stairs, approximately how much carpet (in linear inches of width) is needed per step when measuring tread and riser combined?
- 10–12 inches
- 14–17 inches
- 18–21 inches (Correct answer)
- 24–27 inches
Correct answer: 18–21 inches
A typical tread depth of 11–12 inches plus a riser height of 7–8 inches totals roughly 18–21 inches of carpet per step.
Question 2: For a diagonal tile installation at 45 degrees, what additional waste percentage should be added to the estimate compared to a straight lay?
- 2–3%
- 5–7%
- 10–15% (Correct answer)
- 20–25%
Correct answer: 10–15%
Diagonal installation increases edge cuts at all four perimeter walls significantly, requiring approximately 10–15% additional material beyond a straight layout.
Question 3: In a 3-4-5 triangle method used for squaring layout lines, if one leg measures 3 ft and the other 4 ft, what must the hypotenuse measure for a true 90° angle?
- 4.5 ft
- 5 ft (Correct answer)
- 6 ft
- 7 ft
Correct answer: 5 ft
The 3-4-5 Pythagorean triple guarantees a right angle: 3² + 4² = 5², so the hypotenuse must equal exactly 5 ft.
Question 4: When planning a ceramic tile layout starting from the center of a room, what is the first step before snapping any layout lines?
- Dry-lay tiles from wall to wall to check border widths (Correct answer)
- Apply adhesive to the center quadrant
- Cut all border tiles
- Install transition strips at doorways
Correct answer: Dry-lay tiles from wall to wall to check border widths
Dry-laying a row of tiles from center to wall (without adhesive) lets the installer check border tile widths and adjust the starting point before any lines are committed.
Question 5: A hardwood floor is being estimated for a 14 ft × 18 ft room with an 8% waste factor. What total square footage should be ordered?
- 252 sq ft
- 272 sq ft (Correct answer)
- 282 sq ft
- 272.16 sq ft
Correct answer: 272 sq ft
14 × 18 = 252 sq ft; 252 × 1.08 = 272.16 sq ft, rounded up to 272 sq ft minimum (typically the next full box).
Question 6: What does a 'working line' represent in flooring layout?
- The expansion gap at the perimeter wall
- A chalk or laser line used as a guide for placing the first row or tile course (Correct answer)
- The grout joint alignment mark
- The boundary between two flooring materials
Correct answer: A chalk or laser line used as a guide for placing the first row or tile course
A working line is a snapped or laser-projected reference line from which all installation begins, ensuring rows remain straight and square throughout the room.
Question 7: For an L-shaped room, what is the best approach when estimating flooring material?
- Measure only the longest wall and multiply by the widest width
- Divide the room into two rectangles, calculate each area, then add them together with waste (Correct answer)
- Measure the perimeter and divide by 4
- Order material for a square room enclosing the entire L-shape
Correct answer: Divide the room into two rectangles, calculate each area, then add them together with waste
Breaking an irregular room into rectangular sections, calculating each area, summing them, and applying a waste factor is the accurate and standard estimation method.
CFI Estimating, Layout & Planning 2
When estimating carpet for stairs, approximately how much carpet (in linear inches of width) is needed per step when measuring tread and riser combined?