You will have to make sure your joists can handle the addition of considerably more weight from the plywood subfloor and any floor coverings.
How to level bedroom floors.
To level a floor start by removing the existing flooring.
Then go over any particularly high spots with a concrete grinder so they re level with the rest of the floor.
Then mix leveling compound according to the instructions on the package in a large bucket.
To level concrete floors start by cleaning the floor and filling in any cracks or holes with concrete filler and sealer.
Lay a long level downhill on the floor with one end of the level on the level part of the floor and the other end at the lowest point.
Raise the lower end of the level until the bubble is centered then measure the distance from the bottom of the level to the floor to find the depth of the dip.
On the top side of the floor another fix it idea to lay down new hardwood over the existing floor.
If an engineer found no structural issues you may be able to level the floor by applying a cement based self leveling floor product such as henry level.
Once the compound reaches a creamy consistency pour a thin layer into the sunken sections then smooth out inconsistencies with a hand trowel.
When you re finished spread some concrete leveler primer over the floor and let it dry until it has a tacky.
This demonstration is intended for professionals only.
In this lowe s pro how to learn the step by step process for how to level a floor.