Usually, you’ll construct an interior wall on the floor, then stand it up, wedging it tightly in place against ceiling joists. But if you’re remodeling an existing room, you’ll end up hitting the drywall or plaster on the ceiling and damaging it.
You could build a shorter wall, and then shim it into place or build a non-bearing wall this way:
Decide where the wall is going to go. A wall that runs perpendicular to floor and ceiling joists is better anchored, but of course, you can’t run all walls one way. If accessible, you can install blocking in the basement or attic to provide nailers and stability. Otherwise, run the wall along a joist. Begin your wall at a stud in the existing wall if you can.
Plot out the location of the bottom plate (the 2×4 at the bottom of the wall), and snap a chalkline. Then, use a plumb bob to determine where the top plate should begin and end, and snap another chalk line.
Now cut the top and bottom plates to length. The existing wall may not be plumb, so measure each separately.
Beginning at the end of the wall, measure and mark stud locations on 16″ centers on the top and bottom plate.
Nail or screw your bottom plate through to the joists or blocking below. Then, get some help and do the same with the top plate; start your nails or screws before lifting it in place.
In case the floor or ceiling isn’t level, measure between the plates for each stud, and cut it so it fits snugly. Tap studs into place, confirming plumb with a level, then toenail into the plates.