Mark the length of the new wall on both the adjoining wall and floor.
How to frame a wall on uneven concrete floor.
Cut pressure treated 2 x 4 boards to length and lay them along the chalk line.
Measure all the studs individually and toe nail them into the plates.
Use a long level or a laser to mark straight up from the bottom plates to the ceiling.
Measure and cut two two by fours one of.
Snap chalk lines between each set of marks to guide the wall installation later.
Walls are built from the ground up.
I use tapcon concrete screws to secure the wood to the floor.
Fasten your top plates to the ceiling.
Use an impact driver to drive a 3 tapcon screw through the wood and into the floor.
Use a chalk line on the floor to indicate wall placement and cut a 2 by 4 to fit.
Then remove the tape.
Slip shims under the low end of the 2x4 rail until it s perfectly level then use a scribing tool to transfer the unevenness of the floor onto the rail.
Fasten your bottom plates to the floor where you want your walls.
When a floor is uneven the best way to frame a new wall is to set the floor and ceiling plates first.
In this video i show you the method that i use to attach basement framing to a concrete floor.