CSLB General Building (B)Planning and EstimatingHard
A framer is estimating studs for a 100-linear-foot wall using 16-inch on-center spacing, and will add a 10% waste factor for cuts and corners. Approximately how many studs should be ordered?
- A92 studs
- B75 studs
- C76 studs
- D84 studs
Show answer & explanationAnswer & explanation
Correct answer: D. 84 studs
First find base stud count: 100 ft = 1,200 inches; 1,200/16 = 75, plus 1 for the starting stud = 76 studs. Applying a 10% waste factor: 76 x 1.10 = 83.6, which rounds up to 84 studs.
Why the other options are wrong
- A. This overestimates by applying too large a waste percentage.
- B. This is the base count without adding the extra starting stud.
- C. This is the correct base stud count but omits the waste factor.
Stud Estimating with Waste Factor
A method to calculate wall studs by dividing wall length by spacing, adding one stud, then increasing the total by a waste percentage for cuts and corners.
- Formula: (length in inches / spacing) + 1
- Standard spacing is 16 or 24 inches on center
- Waste factors typically range from 5% to 15%
Memory trick: Sixteen apart, plus one to start, then pad it for the waste cart.