How I finally solved deck post shifting — steps that actually worked

I had a similar scare with my back deck last April. My 6x6 posts were starting to lean because the original builder used those thin nails instead of proper fasteners. I bought a 12-ton bottle jack from Harbor Freight and used a scrap piece of LVL to spread the load across three joists. It’s nerve-wracking hearing the wood creak when you start pumping that jack, but once I got it up about a quarter-inch, I could see how much the pier had actualy tilted. Instead of just repositioning, I ended up swapping out the old brackets for Simpson Strong-Tie ABW bases. I found that the original ones didn't have enought of a lip to keep the post from walking during a heavy freeze-thaw cycle. I used 3-inch GRK structural screws to tie everthing back togehter. It felt way more solid than the old lag bolts I had in there before, which were already starting to rust out. One thing I’d add is to check your joist hangers while you have the weight off the post. I noticed two of mine had pulled away about an eighth of an inch, prolly from the stress of the shift. Tightening those up while the deck was leveled saved me alot of trouble later on.

While you have the structure elevated, I woud strongly suggest verifying that the lateral shift hasn't introduced any unintended racking or torsional stress at the ledger board connection, as even a minor three-degree deviation at the pier can translate into significant shear pressure on those primary carriage bolts. It is also a prime opportunity to inspect the post-to-beam connection for any hairline fractures in the grain that might have occured during the freeze-thaw cycle’s movement, particularly if the original installer failed to utilize a proper standoff base to mitigate capillary action and subsequent internal rot. I found that using a simple plumb bob alongside the jack provides a much more reliable vertical reference than a standard spirit level.

I'm curious if you've acutally ruled out the footer depth as the real culprit here. Swapping brackets and structural screws is great for keeping the post from walking, but have you checked if those piers are actually below the frost line? If the concrete is heaving beacuse it was poured too shallow, you're just going to be jacking this thing up again every two years. I'd be worried that locking it down too tight without fixing the base might just cause the bracket to pull right out of the concrete when the ground moves next February.

Seen this a hundred times back when we used to just pour 'em on a bed of gravel and hope for the best. Everyone loves those fancy Simpson ties now, but back in the day, we’d just notch the post over the beam or use heavy-duty angle irons we'd weld up ourselves. If you're jacking that thing up, keep an eye on your railing tension too. I’ve seen guys get the post back in place only to have the top rail pop right out of the house siding beacuse the whole frame shifted an inch to the left. Might want to loosen your rail hardware before you start pumping that bottle jack, or you'll be fixing more than just a bracket.