Jacking up the deck and shimming the post can resolve deck sag problems.
How to lift or jack up sunken floor joists.
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.
Raise the jack so it contacts the wooden floor joist supporting the decking.
You cannot jack up a house in one day.
Generally there are posts and beams under the floor joists.
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.
It has to be jacked up slowly over days or even weeks to avoid cracking drywall plaster windows and even structural elements.
Continue raising the jack until the deck is no longer.
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.
Jack up that portion of the house and place new footers.