The Steel Insert System (US Patent #8061106) is designed for structural pergolas. Structural Pergolas using 5x5 posts or columns both begin with  3" or 4" 40wt galvanized pipe, either set in concrete or core drilled into a concrete pad. Post Adapters and Post Adapter Plates enable the posts to have the internal strength needed for a large structure. Rail Adapters, Rail Connectors, Column Adapters and Stainless Steel Powder Coated Beam Brackets allow the carrying and cross beams to be joined, creating a heavy duty metal to metal connection. All beams must be filled and through-bolted for uplift protection. For detailed instructions on installing a structural pergola using 5x5 posts, click written or illustrated. For detailed instructions on installing a structural pergola using columns, click written or illustrated.