Code Copmpliant Stairs in Rental Property?

[Preston Roper]

I have a property that i am looking at renovating. I have a solid budget and plan the only thing that i am worried about is the stair case to the second floor/ attic. The property was built in the 40s so when they built it there where very few regulations on stairs treads, riser height ect. The stairs have a narrow tread and a slight spiral in the beginning. They by no means meet code but i believe are grandfathered in (as long as i leave them the way that they are). My question is, if i renovate the house but leave the stairs alone how much more liable could i be if a tenant slips and falls? The stairs lead up to a finished attic that will be the 3rd bedroom.