Lumber ? ? ?

[charlie_the_tuna]

if you look closely in the second picture you can see the stairs coming of the wall on the left side.

[tsubaki]

Are you sure the problem lies only with the lower joists?

I live in dryrot and termite heaven, usually the problems (at least around here) is a multiple thing.
House foundation settleing, sills seperating from the floor level, etc.
Have you poked around and made sure there aren't any other problems causing this?

[macojoe]

I think you will be tearing into that wall on the right, You going to need to rebuild it and level it for new stairs. Foundation must be settling for some reason on that side?

[tsubaki]

Yeah, I can't make no sence of it not actually being there.
Look also if the walls seem to have gotten farther apart in some locations.
Don't be surprised if the house ain't square or level, few actually were (mine ain't, it was added on to in 1957)
Have someone help you (or drive a nail) pull a string tight from one end of the room to the other in every possible direction, measure or eyeball and see if the problem keeps showing up in the same place.
Normally you see this problem on exterior walls where the nails have rotted off, not on the interior side of the stairs

[lumberslinger178]

Hey Chuck ,
looks like the sagging towards the right going to the second floor...... hmmm sounds like you may just need a little extra beef under th handrail side in the basement.
with the age of the house it will never be perfect without major work . I'd say just get one of those colums that you can adjust ... and just give it a half turn or a quarter turn once a week of so.

btw I like the newel post looks like chestnut.

[msbhammer]

You need to reinstall the smoke alarm that is missing on the ceiling in the first picture.

[parishht]

CTT, I live in an old brick farmhouse built in 1820.
I have the same broblem with all my walls and stairs.
The best you can do is to shore up the main beams in the basement.
Jack them slowly to get them were you want them.
only go about 1/2 to 3/4 inch at a time.
I have a center chimney which the main beam is into
and the joists are on top of the sill.
dryrot over the years has eaten away at the ends and the floors are like ocean waves.
I am leveling everything in steps so as not to do any major damage.