Flatbed Tarp Coverage, Count, and Weight

The width requirement is the one people get wrong, because a tarp has to come down BOTH sides: a load eight feet wide and six feet tall needs twenty feet of tarp across before any allowance for tucking under the edge of the load and getting a bungee on it, so the width needed is the load width plus twice the height plus twice the tuck. A tarp sized to the deck width is not a tarp, it is a lid. The length side is a shingling problem. Tarps overlap toward the rear so road wind cannot get under a leading edge, and each overlap costs its length from the run, so three twenty-foot tarps with four-foot laps do not cover sixty feet, they cover fifty-two. The weight line is not a footnote: a steel tarp runs 60 to 100 pounds, so a three-tarp load is a couple hundred pounds of payload and, more to the point, a couple hundred pounds a driver has to get onto a load by hand, which is where tarping injuries come from. A 40 ft load 8 ft wide and 6 ft above the deck needs 8 + 12 + 2 = 22 ft of width, which a 27 ft tarp clears, and ceil((40-4)/(20-4)) = 3 tarps covering 52 ft at 195 lb. Raise the load three feet and the width requirement passes what a steel tarp can do, and the answer is lumber tarps. A planning estimate; the actual tarps on the truck and the driver's own judgment govern.

width_needed_ft = load_width + 2 x load_height + 2 x tuck; tarps_needed = ceil((load_length - overlap) / (tarp_length - overlap)); covered_length_ft = tarps x tarp_length - (tarps - 1) x overlap; total_weight_lb = tarps x weight each.

Flatbed tarp coverage from the wrap geometry -- width equals the load width plus twice the height plus twice the tuck, because the tarp comes down both sides -- and the shingled-overlap length relation, by name; standard flatbed practice on public geometry. The actual tarps on the truck and the driver's judgment govern.

The coverage geometry is public. The load and tarp dimensions, the overlap, and the tuck allowance are the driver's own values.

Estimate. AHJ and licensed professional govern.

Field names used by the API: load_length_ft, load_width_ft, load_height_ft, tarp_length_ft, tarp_width_ft, overlap_ft, tuck_ft, tarp_weight_lb, width_needed_ft, tarps_needed, covered_length_ft, total_weight_lb

• Width comes down both sides width = load width + 2 x height + 2 x tuck; a tarp sized to the deck is a lidflatbed practice
• Shingled overlap each lap costs its own length from the run; tarps overlap toward the rear so wind cannot get under a leading edgeflatbed practice
• Weight is handling 60 to 100 lb per steel tarp, lifted by hand onto the loadflatbed practice