Assuming that you've jacked the house up to get rid of the sag, and you've constructed temporary supports so you can remove the wood posts, all you really need to do is install new lalley columns in their place. Set the base plate right on the existing concrete pier (if it's still in good shape), set the lalley column on it with the top plate between the column and the beam, nail the top plate into place once the column is plumb, and set the load back down on the column. When both columns are in place, re-pour the floor around them. The concrete floor poured up against the column base will keep it in place.

I won't be using a lally column, which I now understand is concrete filled. I'll be getting hollow steel support posts from a local supplier. They make two kinds, "schedule 40" and "scheudule 11" (referring to BOCA which I'm not an expert on), with the schedule 40 being significantly stronger. Each is "permanent", but has 3 inches of play built in via an adjustable bolt at the bottom. I like your idea about setting the post in the hole and filling it with concrete. I'm just not sure I'd be able to reach the bolt with a cresent wrench to tighten it and raise the top plate against the main beam with the post already standing in that small 6" by 6" hole. In order to get the post in the hole, it can't be fully extended. I can only adjust it up the final inch or two after it is sitting vertically in the hole. Then, the hole is only 6" by 6" so I wouldn't be able to get the wrench around the bolt. That is why I'm playing with the idea of filling the 6 by 6 hold with concrete first, letting it cure and then setting the new post on that. However, I like your idea about cementing it in. That would provide much greater stability. I have a lot to think about!

Thanks again!

Mike

The idea of the whole thing being an adjustable column support requiring a crescent wrench to tighten it is also just a little troubling. How does on insure that the column has been raised to maximum bearing on the beam above? Well, like I said, that's only my experience...lacking any with these type of supports you describe. The closest I've come is the pipe jacks used for temporary support when lifting a structure or beam (like yours) in order to construct additional temporary stud partitions while installing new lally columns. The jacks afford the opportunity to actually "lift" the structure to a position just a little higher than the final position so that after the lallies are in place, the load can be lowered to it's final resting position, rather than lifted into it. I find that to be a more comfortable fit, especially when dealing with a sagging beam that needs to be brought back into original position in order to save the structure.

Anyway, good luck.