... certificate 3.Economical structure,Modern Looking. ISO9001&ASTM steel roof truss/Industrial building / prefabricated factory Qingdao Baoduo Steel ... Q345B,Q235BColumn&Beam: Welded or Hot rolled H-sectionWall&Roof: EPS, Rockwall, PU sandwich ,corrugated steel sheetDoor: Rolled ... or sandwich panel sliding doors,9.accessories:semi-transparent skylight belts, Ventilators, down pipe, out gutter etc10.local ...