If a pier that the post is standing on has sunk into the ground you will need to lift the beam off the post and replace the post with a taller one.
How to lift or jack up sunken floor joists.
Get the jacks under the floor.
Once the new joists were up we found locations where the concrete blocks could sit flat on the ground so the pressure wouldn t cause them to crack.
Anything involving 20 ton house jacks will take time.
Generally there are posts and beams under the floor joists.
It has to be jacked up slowly over days or even weeks to avoid cracking drywall plaster windows and even structural elements.
Raise the jack so it contacts the wooden floor joist supporting the decking.
Identify the area of the deck that is sagging and locate the support post that needs to be shimmed.
After they were in place we hoisted up the 4 x6 x8 beam so that it crossed all four of the new joists sliding the screw jacks underneath.
Jacking up the deck and shimming the post can resolve deck sag problems.
Continue raising the jack until the deck is no longer.