I have a pole building that's about 20 years old, and some of the posts are starting to show rot damage at ground level. (Inset rant about the quality of recent pressure-treated lumber). The structure is a bit complicated to describe, but basically, it's a room over a breezeway, supported on 6x6 pt posts. Because of the weight of the room, it would be inviting disaster to remove the posts to replace them. In any case, the posts are embedded in the second story, so they could only be replaced part way up and spliced below floor level. So far, there is no sign of settling or shifting, but obviously something has to be done before the damage becomes more extensive.
Some of the repair methods that come to mind: Dig down to the footing (the posts are set on concrete pads below frost depth) on one side of the post, insert another 6x6, and band or bolt it to the existing post. Seems to work with utility poles.
Same thing, but with 4x6s on opposite sides of the post.
Dig down part way, all around the post and pour a concrete collar a couple of feet below ground and a couple of feet above. I understand that encasing the post in concrete all the way down to the pad with no provision for drainage would promote further rot.
Build a dam around the post, drill holes in it, and try to saturate it with one of the resin systems designed to stabilize rotting wood., possibly combined with one of the other solutions.
I realize that whatever I do will require some excavation, but I'd like to keep it to a minimum. As I mentioned above, the structure is perfectly stable so far and I'm terrified at the prospect of de-stabilizing it by undermining its support.
