Abstract: An out-of-doors prefabricated, pre-engineered vertical wall structure constructed entirely of pressure treated wood and comprised of successive individual wall sections tightly arranged in an end-to-end pattern. Supporting rectangular posts join immediately adjacent wall sections together end-to-end and occupy the entire space between the sections, each of the posts having flat surfaces facing the ends of immediately adjacent wall sections on opposite sides of the post with upright pairs of spaced cants secured to said flat surfaces so as to form upright channels extending upwardly from top to bottom on the posts, each pair of cants being spaced apart to receive one end of one of said wall sections in a tight relation between said cants.