How to Anchor the Wall to a Concrete Floor

Stand the wall upright and attach one end to the existing frame with a framing nailer or screwgun. Make sure the entire height of the wall is well secured. Use at least one fastener every 18 inches.
Use a powder-actuated nail gun and 2 ½-inch hardened concrete nails to attach the lumber baseplate of the wall to the concrete.

Make sure the wall's baseplate is in the correct position.
Use a tape measure and chalkline to mark the correct position on the concrete floor. Make a line for each edge of the wall for easy alignment. Fasten the wall to the floor starting from the end attached to the existing frame. Move along the wall from this point fastening as you go. This will allow minor adjustments in the wall's placement down the length of the wall to insure that the entire wall is straight.

Properly wear hearing and vision protection and read all safety instructions before proceeding. Load the charge and fastener into the gun according to manufacturer's instructions. There are two basic type of powder-actuated nail guns. Automatic guns have a trigger mechanism, much like a firearm. Hammer guns are activated with a blow to the firing pin bolt on the top of the gun. Consult the manufacturer's instructions for specific operating instructions.

Place the barrel of the gun where you want the nail to be driven. For automatic guns, apply weight to the gun to depress the barrel safety and pull the trigger. For hammer-activated guns, place the barrel in position and apply pressure to compress the barrel mechanism. Hold the gun securely and strike the firing bolt on top of the gun with at least a 20-ounce hammer using enough force to activate the charge.

Choose the correct powder charge for the job. Charges come in several strengths and are color-coded. Follow manufacturer's recommendations for the best results. Repeat the process between every stud, and again at each side of any door.