Erecting this structure takes only a couple of days, several days apart: one to dig postholes and set the posts, another -- after the concrete cures -- to cut and assemble the components. We used pressure-treated 4x4s for the posts and, to add to the beauty of the arbor, redwood for the superstructure.
1. Erect two posts. Sink the 4x4s approximately 5 feet apart, setting them at least 2-feet deep, or down to the frost line. Secure with concrete or packed soil. Cut off so the tops are approximately 7 feet above ground level. Lag-screw two short lengths of 2x6 to each post. Check to be sure crossbeams are square with the posts before tightening screws.
2. Shape the beams. Use a jigsaw or router to shape a decorative motif at the ends of two longer beams. Drive at least two nails through these into the ends of each crossbeam.
3. Top with cross pieces. Cut 2x2s to length and drive one nail through each into each of the longer beams. To minimize measuring, use spacers, short scraps of wood to assure that the ends of the boards extend the same distance beyond the outside trusses.