Part of my tri-level house is supported by a crawlspace. The crawlspace has 3 rows of six 4x6 posts sitting on concrete piers. A couple of weeks ago I noticed that the bottom of three of the posts were not touching their respective concrete piers; they were floating a fraction of an inch above the the pier.
I hired a structural engineer to come look at the issue. The sinking piers are likely due to water + soil issues. (We did install a sump pump after moving in a few months ago because there were several inches of water down there after heavy rains.)
Longer term, I'm hoping the sump pump can help stop the settling of the piers. Perhaps I'll add a drainage system around the house too in the future.
I want to fix/replace these posts so that they are again supporting the floor girders. My plan is to jack up the girder 1/8th of an inch, remove the old post, cut & replace it with new 4x6 PT post that is the proper length, then remove the jack.
I am considering just placing a piece of metal in between the bottom of the new post and the pier (so that contact + weight keeps the metal in place) but not physically attaching the post/metal/pier with screws or nails. Do I have to physically attach the bottom of the new posts to the concrete pier? My concern is that if there is continued settling and the post is physically attached to the pier that (1) I will not notice that there is settling because the gaps won't appear underneath the posts, and (2) the weight of the sinking concrete pier could pull down the girder due to its weight, more so than it would if the post were just 'free.'
Even if there is continued settling, is it best to make sure the post is attached to the pier rather than just sitting on it?
For what it's worth, none of the other posts have any base bracket of any kind. Most have some 6 mil and/or roofing shingles sandwiched between the pier and post.