Bridging by span, 1926.757(d)
- At or above the Table A or B span: one row of bolted diagonal erection bridging near midspan.
- Over 60 ft through 100 ft: two rows of bolted diagonal erection bridging near the third points. No more than two employees on the span until all other bridging is anchored.
- Over 100 ft through 144 ft: all rows must be bolted diagonal bridging, hoisting cables may not be released until all bridging is installed and anchored, and no more than two employees on the span.
- Over 144 ft: erect in accordance with 1926.756, the beams and columns section.
Trap: "nearest midspan" for the 90 ft band misreads the regulation; 1 ft is a load placement limit, not a bridging location.
No construction loads until bridging is complete
Under 1926.757(e)(2), no construction loads until all bridging is installed and anchored and all bearing ends are attached. Insulation on half-bridged joists is not allowed. The only exceptions are the two bundle provisions below; the 4,000 lb decking figure does not cover insulation.
Bridging bundles, 1926.757(e)(3)
A joist bridging bundle may be landed early if it is no more than 1,000 lb total, placed on at least three joists secured at one end, with the bundle edge within 1 ft of the secured end.
- 1,400 lb of bridging: 1,400 ÷ 1,000 = 1.4, rounded up to 2 bundles. Three comply but are not the fewest.
Decking bundles, 1926.757(e)(4)
A decking bundle may be landed early only if every condition is met:
- The employer has determined it is safe.
- At least three joists.
- Joists attached at both ends.
- At least one row of bridging installed and anchored.
- Bundle of no more than 4,000 lb.
A 3,600 lb bundle on three joists attached at both ends still fails with no bridging row. Traps: 1,000 lb and joists secured at one end are the bridging bundle conditions, not decking.