As we all know, PT posts will crown and twist during a deck build. To compensate for that movement, when installing posts that will support a deck beam and ultimately become part of the deck’s railing system, I initially fasten the bases to their metal post bases with only three screws, instead of the seven or so per side typically called for by the post-base manufacturer. Later, after the deck has been framed and the decking installed, I can go back to the post base connections, quickly remove those screws, and adjust the position of the post bases until the tops of the posts are perfectly aligned.
Install the post-base hardware with the bracket perpendicular to the beam, and fasten the post to the bracket with just a few screws.
Once the tops of the posts are aligned and the top rail installed, go ahead and fill the remaining holes in the bracket with fasteners.
Of course, the design of the metal hardware means that posts can be adjusted in only one direction. So when installing the post-base hardware, I orient the brackets so that there is play in-and-out rather than side-to-side. This makes it easy to knock the posts a little this way or that way to get the top rail perfectly straight. Because I’ve driven in only a few screws at first, I can reposition the post bases and drive in new screws in the unfilled holes without worrying that the screws will find their original holes. Once everything is aligned perfectly and the top rail is in place, I go ahead and finish driving all of the remaining fasteners into the post bases.
