Three limits, three different gaps
29 CFR 1926.754(b) sets three separate limits, and the exam swaps their figures as distractors. Two use "whichever is less": compute both numbers and take the smaller.
Eight stories to the uppermost permanent floor
Under 1926.754(b)(1), there may be no more than eight stories between the erection floor and the uppermost permanent floor, except where the structural integrity is maintained as a result of the design.
- An erection plan calling for 10 stories, with a design that does not address stability at that stage, fails. Ten exceeds eight.
- Four floors or 48 ft is a different limit and does not replace this one.
Four floors or 48 ft of unfinished bolting or welding
Under 1926.754(b)(2), there may be no more than four floors or 48 ft, whichever is less, of unfinished bolting or welding above the foundation or the uppermost permanently secured floor, except where the design maintains structural integrity.
- 10 ft floor-to-floor: four floors = 4 × 10 = 40 ft. 40 ft is less than 48 ft, so 40 ft governs.
- 48 ft ignores "whichever is less".
- 80 ft comes from the eight-story rule (8 × 10 ft), a different gap.
Planked floor or nets within two stories or 30 ft
Under 1926.754(b)(3), a fully planked or decked floor, or nets, must be kept within two stories or 30 ft, whichever is less, directly under any erection work being performed.
- 18 ft floor-to-floor: two stories = 2 × 18 = 36 ft. 30 ft is less, so 30 ft governs.
- 36 ft picks the greater figure.
- 18 ft is one story.
Quick sort
- Eight stories: erection floor to uppermost permanent floor, 1926.754(b)(1).
- Four floors or 48 ft, whichever is less: unfinished bolting or welding, 1926.754(b)(2).
- Two stories or 30 ft, whichever is less: planked floor or nets under the work, 1926.754(b)(3).