How to fix sloping floors, upper floor

[Srixon]

What I did to level (sala) my floor. I cut the tongue, removed it, and glued and screwed battens at the right height and blocked at each floor chip joint.

 

[Srixon]

In the picture, are the planks (sponten) already cut?

 

[Himmelsfararen]

What I did to level (sala) my floor. I cut the tongue, removed it, and glued and screwed joists at the correct height.
Then I laid chipboard flooring.

Absolutely, as long as they saw on the right side of the nail in this case.

 

[Himmelsfararen]

In the picture, are the planks (sponten) already cut?

I agree. Looks tricky but I read what TS wrote about them going under the bathroom, I may have misunderstood...

 

[aelamik]

What does the ceiling on the lower floor look like, does it slope as much as the upper floor?

We haven't opened it up to see how the boards look, but from the ceiling that can be seen, which is in such molded tongue and groove boards, I might see a slope along the faulty beam. I'll measure with the level tomorrow!

 

[aelamik]

@Himmelsfararen and @Srixon, I apologize for the lack of clarity. I posted a photograph without explaining it. The cut board is the side facing the neighbor. I included it to show how they were attached. I can't get a really good photograph of what it looks like on the side facing the bathroom, but it appears to be a stud (wall) on the planks. And I assume they are nailed into the joists directly under the wall then.

 

[Himmelsfararen]

@Himmelsfararen and @Srixon, I apologize for the lack of clarity. I've posted a photograph without explaining it. The cut board is the side facing the neighbor. Included it to show how they were attached. Can't get a really good photograph of how it looks on the side facing the bathroom, but it appears to be stud (wall) on the planks. And I assume they are nailed into the joist directly under the wall then.

No worries, hope it gets resolved in a good way!

 

[aelamik]

Again, thank you for responding! 🙏
The floorboards are nailed to each beam along the entire floor. So reasonably, they should also be nailed to the beam directly under the bathroom wall. If that's the case, I should be able to cut the floorboards on the bedroom side of the bathroom wall without risking the bathroom collapsing.
My concern then becomes what might have caused the beams to sink this way. There are also quite a few beams in between that would also need to have sunk slightly for the slope to be somewhat consistent. Could there be something wrong with the load-bearing wall on the first floor? Is there any way I can investigate this myself?

 

[Himmelsfararen]

Again, thank you for responding! 🙏
The planks are nailed into each beam along the entire floor. So reasonably, they should also be nailed into the beam directly under the bathroom wall. If that's the case, I should be able to cut the plank on the bedroom side of the bathroom wall without risking the bathroom collapsing.
I wonder then what could have caused the beams to sink like this. There are also quite a few beams in between that must have sunk a bit for the slope to be somewhat consistent. Could there be something wrong with the load-bearing wall on the first floor? Is there any way I can investigate it myself?

Keep in mind that your new floor in the bedroom must have a beam to rest on next to the wall. Can you "shim" a new beam at the right height on the old beam that is under the wall? (Glue and screw) If you have an original plan sketch, you'll see if any wall has been removed on the lower floor. An easy way is to measure the height of the same stretch downstairs and see if it sinks the same, check in the basement too, it could be a secondary issue... (Not likely). It could be an under-dimensioning so that it has finally failed to support, I assume the house is old. Do you think the wall has sunk 50 mm, or that the beam bends 50 mm over a span?

 

[aelamik]

Remember that your new bedroom floor must have a joist to rest on next to the wall. Can you "block" a new joist at the correct height on the old joist that is under the wall? (Glue and screw) If you have an original floor plan, you can see if any wall has been removed on the lower floor. It's simple to measure the height on the same stretch downstairs and see if it sinks the same, check the basement as well, it could be a consequential error.. (Not likely). It could be an under-dimensioning, so it has eventually not been able to hold up, I assume the house is old. Do you think the wall has sunk 50 mm, or that the joist is bending 50 mm in a span?

Absolutely! I'll make sure I can do that even before I cut any tongue. I should probably buy such an inspection camera. No walls have been removed on the ground floor. The townhouse is from 1965. I had concerns about consequential errors, but after reminding myself that the foundation is concrete with concrete floorboards on the ground floor, it didn't seem reasonable (perhaps I'm wrong?). The remaining options (according to my limited expertise in the area) are that the joist has bent, but perhaps more likely been overloaded? My reasoning is that for the other joists to 'follow along', the load-bearing wall on the lower floor must also have been affected in some way. The bathroom upstairs was renovated in 2015 with a cast floor. Maybe it's heavier than the structure can tolerate? 😮

 

[Himmelsfararen]

Absolutely! I will make sure I can do that before I cut any studs. I should probably buy such a peephole camera.
No walls have been removed on the ground floor. The townhouse is from 1965.
I had concerns about consequential errors, but after reminding myself that the foundation is concrete with concrete beams on the ground floor, it didn't seem reasonable (perhaps I'm wrong?). The remaining alternatives (according to my limited competence in the area) are that the beam has bent, but perhaps more likely has been overloaded? I reason that for the other beams to 'follow along,' the load-bearing wall on the lower floor would also need to be affected somehow. The bathroom upstairs was renovated in 2015 with a cast floor. Maybe it's heavier than the structure can handle? 😮

Here you can compare with what you have if you can see the thickness of your studs. A bit to fill in, but try your way forward. https://www.byggbeskrivningar.se/dimensionering/golvbjalklag-inne/