I am replacing all of my front porch columns and railings. I am using pressure treated lumber with 2" x 4" for the verticals and 2" x 6" for the horizontal top & bottom pieces. The wood I am replacing is of the same dimensions and appears to be connected with 2 screws through the bottom and 1 screw through the top of each vertical piece.
I would like to use pocket holes but have some concerns. Note that the vertical pieces really only need to be held in place plumb and evenly spaced, they will not carry any load. I know that the wood will move as the weather changes. I am reluctant to glue, secure with 4 pocket holes, & caulk these vertical pieces. Wouldn't they break free or bow over time? Plus, I have 54 of these to attach. That's a lot of pocket holes to plug, sand, prime, & paint. Also, how would the plugs hold up for outdoor use glued into pressure treated lumber?
It seems that I may be better off securing the verticals with 2 screws through the bottom (to prevent twisting) and 1 in the top. Filling the holes will not be fun, but the pocket hole solution would not prevent that either.
I do plan to use pocket holes to secure the horizontal sections to the columns and for the columns to the headers.