A slant slope situation might be one where over the course of 15 or 20 horizontal feet the floor slopes down one or two inches.
How to fix sloping floors on second floor.
Except for that slope the floor itself might be flat.
Depending upon the conditions it is possible to strengthen or repair existing framing members such as floor joists or roof rafters by adding reinforcing material sandwiching the member on either side with plywood is sometimes worthwhile but the plywood must be installed correctly for greatest strength.
If a load bearing wall is removed on the first floor then the second story floor joist or trusses may drop down in the area where the load bearing wall was removed.
Slanted floors can also cause cracks over windows and doors or make doors and windows stick and tough to operate.
There are several problems that can cause a sagging or sloping floor which is one of the reasons why fixing a sloping floor is difficult.
Thre ways to fix a sagging or sloping floor.
The cause of these may be the same or may be different.
Load bearing wall removed or altered on first floor.
Foundation issues deteriorating wood supports especially sills which rest on the foundation footer improperly installed joists or sub floors and other issues can all cause a floor to slope or sag.
Sagging floor issues often relates to framing issues or the loads that the floors are carrying.
Sloping floors verses sagging floors these terms are related and a sagging floor actually has a slope from each side of the sag.
Thus by repairing your out of level floor you may find the windows and doors in your home are a whole lot easier to use and last longer.