Subfloor for joists with 900 cc?

[Flygrekord]

I've knocked down 3 walls in the apartment and realized that the floor is not on the same level anywhere, it even slopes inside the original rooms. So I thought about laying a new subfloor to make it "level," but the problem is the joist spacing is 900 mm center-to-center and not 600 (which is recommended?). The house is 120 years old and no one seems to have noticed this before. Today, there's rough tongue and groove boards or something similar from the time it was built. Can the chipboard flooring handle 900 mm center-to-center spacing?

 

[larsbj]

No, you need to lay something better than just chipboard. For example, tongue and groove boards + chipboard or just solid tongue and groove boards.

 

[larsbj]

Or maybe a sparse panel under the floor chipboard