At the ends of the marks, measure out 8 feet from the curved patio wall (for this particular project only) and mark the exact location for the two front columns. Take exact measurements. You can use scrap pieces of the column as a template for the brick. You may decide to place the column on the center of the brick. This makes drilling the holes for the anchor pins easier. Once you trace around the column, use a square to mark the center. Repeat the same procedure on the rear columns. And be sure to set the columns slightly away from the wall. To mark the center column simply measure between the two columns at the back. Mark with a square just like the rest.
Before you do anything else, paint the lumber while it's still on the ground. A lot of wood is involved in this project, so it's easier to put the first coat on now. Depending upon the climate, treated Southern pine can take up to completely dry. You should hold off painting, staining or applying any type of finish until you're sure the wood is completely dry.
Now it's time to get the columns set where you need them. To make sure the columns stay put once they're in place, be sure to use steel rods (Image 1). First, cut each column off at 8 feet. Since the columns are hollow, you'll need to cut down a 6 x 6 piece of lumber to insert into the column -- simply hammer the post into the column. Stop just before the final portion is inserted and nail a piece of lumber lengthwise (Image 2) in order to make sure you don't hammer the post too far into the column. Add some 3" wood screws to make sure the post is secure and will stay in place. One screw per side should suffice.
Measure and mark 20" from the bottom and 12" from the top of the column, and use a router to smooth the corners. Lightly sand the edges as well. Use a jigsaw to drill out a hole in the center of the posts. Now the columns are ready to paint.
To get the patio ready for the columns, drill a 1" hole in the brick using a hammer drill. Mark each steel rod allowing 13" above the hole, and then insert the steel rods into the holes, making sure to keep them plumb. Hammer the rods into the ground. Once the rods are hammered and secured, simply slide the columns down over the rods. Use a level to make sure the columns are plumb.