Timber Frame Pergola with remote control phantom screens, LED lighting, and Stereo. Don't let your builder simply set posts on piers for a structure this size. The columns are 4" square 1/4 wall steel that run through the deck and into 36" x 40" deep caissons with engineered steel reinforcement. The steel is wrapped with resawn cedar to simulate a solid wood post, as well as provide a hollow channel in which wiring is run. The exposed brackets and fasteners are custom cnc plasma cut decorative elements. All other fasteners, such as purlins and rafter to beam, are concealed and/or traditional mortise and tenon.