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 up hardwood floor.
The thickness of hardwood flooring boards is known as the profile and profiles vary.
If the floor slants irregularly cut strips that bridge the cap at each floor joist.
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 pro self leveling underlayment available.
Clean it well with a wet dry vacuum.
This will expose the subfloor underneath which is where most leveling problems lie.
Pass a long carpenter s level or.
You can leave linoleum or sheet vinyl in place if it s difficult to remove or if removal would damage the sub floor.
As the posts slowly rot and melt into the floor the house settles accordingly bottom to top.
Screw the strips into the floor joists or subfloor.
Spread the leveler over the floor with a trowel or a gauge rake so it covers each low area completely.
Watch our step by step video showing how to level a wooden floor with expert advice and top tips to help you complete the job with confidence.
Pound nails into the subfloor with a hammer and set screws slightly below the surface of the subfloor with a screwdriver.
Pour a generous amount of mixed leveler onto the subfloor focusing on one or more wavy areas.
Use a pry bar to pull up hardwood floors one section at a time or unfasten carpet or laminate and roll it up from one end.
Use screws to secure the leveling strips to the floor every 16 inches.
A plywood subfloor will bridge any minor waves in the existing floor and leveling compound would help too.
If the level is in the bubble you re ready to go.
To do this you ll want the longest level you can find.
If the bubble is off raise the low end until it s level.
On the top side of the floor another fix it idea to lay down new hardwood over the existing floor.
Otherwise lay a very straight metal bar or wood board on the floor and place a level on top.
If the subfloor is the same in both rooms connecting the two rooms with an even floor shouldn t be difficult.
Be suspicious of wood posts set on dirt floors or wood posts with concrete poured around the post bases.