... cost steel roof construction structuresSome information about the products .1. Vertical Support #1: For each 6-Car Carport, ... inch thick steel2 Diagonal Support Beams are square HSS steel tubing, 4 inches by 4 inches, .125 ... For each 6-Car Carport, we need 6 Roof Support Beams.Rectangular HSS steel tubing 10 feet long, ... jpg) For each 6-car Carport, we need 12 pieces of PurlinCEE Steel 27 feet long, 8 ...