Allowable loads and deflections: U - Uniform load (lb./ft.), C - Concentrated load (lb.), D - Deflection (in.). Spans to the left of heavy line produce a deflection of 1/4" or less under a uniform load of 100 lbs. per square foot. For Perf-O grip product widths greater than 12", use of grating splice kit is recommended to mechanically join butt ends of length.