You can buy premade arbor kits from just about any store but most will be thin, flimsy and use inferior hardware. Building your own however will allow you to control the quality and size to fit your exact needs and save you money if you want to do a little sweat equity. It is really pretty easy, a good weekend project for almost any skill level.
Arches and Arbors
Arbors are typically wider than they are deep and commonly only use 2 vertical posts as opposed to Pergolas that are more square shaped and have more area underneath. Common posts for Arbors are 4x4 or 6x6 and come in a variety of grades and millings.
4" x 4" to 12" x 12" or larger
We recommend using Simpson Strong Drive Timber Screws for all arbor and pergola construction. The Strong Drive Timber Screws are made from 316 Stainless Steel with a Double-barrier coating to resist corrosion and staining