Uneven basement floor
I am framing a basement in 2x3 studs using pressure treated lumber for the bottom plate, which I intend to drive into the floor with a Ramset gun. This is my first framing project and I have already run into a problem. The concrete floor of the basement slopes slightly downwards as it moves away from the concrete walls. This makes the bottom plate slope as well. What to do?
The only thing I can think of is to measure the angle of slope and use a table saw to shave of the appropriate angle off of bottom of the plate so it'll sit flat on the basement floor. It sounds like there should be an easier way.
Can I shim the bottom plate - raising one end so that it lays flat? Do the shims have to be pressure treated as well?