OK got it, using 2X and string lines to see which studs are low and high. Once I have the low and high spots figured out (furthest and closest to the string) what is the next step? How do I ensure that those studs that I intend to sister on stay even with each other?
Completely gutted 16' x 10' room. House has been jacked up as far as it could go. Removed the lathe and plaster (was in very poor shape) Used laser level to find low spots on floor and ceiling. Sistered 2 x 6's on the old floor joists and 2 x 4's and 2 x 6's on the ceiling. Put 3/4" plywood on...