Several years ago, I was hired to install railings and decking on a deck frame that had been built by someone else. I was particularly concerned about the stability of the railing posts, so I reinforced the post-to-frame connections with 1/2-inch-diameter HDG threaded rod. This detail worked so well, I now use it for all types of railings where the post is external to the frame (see photo, top right). It has never failed to win the approval of a building inspector.
Threaded rod is inexpensive and widely available; for a slightly better price, I buy 10-foot lengths in quantity and cut them to size, being careful to treat the end cuts with cold galvanizing paint. Besides being less expensive than Simpson Strong-Tie DTT2 deck post connectors, threaded rod is usually easier to install, and the resulting connection is not only rock-solid, but also adjustable. By placing washers and nuts on both sides of the framing members that the rod passes through, I can make fine adjustments to perfectly plumb up the posts.
Depending on the location of the post and the orientation of beams and joists, I may run the rod through multiple joists, though it’s not always necessary (see photo, bottom right). I usually also reinforce beams and joists with blocking—it’s cheap insurance that also adds stability. Once all the nuts have been tightened, the posts feel as solid as if they had been placed in concrete.
Mark Ellis owns Creative Redwood Designs in Los Gatos, Calif.