We use both Flocoat & Gatorshield galvanized tubing We use 2×4, 2.5×2.5, 2×2, and 1.5×1.5 tubing in both 14 gauge and 11 gauge same decking and roofing options as the aluminum docks. All welded construction on galvanized steel. For more information about the galvanized steel we use, visit usw.com