A Z bar is used when transitioning from carpet to a hard flooring surface such as laminate or hardwood. It is called a Z bar because of its shape, which resembles the letter "Z" and has one smooth side and one side that has tiny metal teeth to grip the carpet. The Z bar creates a smooth transition between carpet and other flooring, leaving a flat surface while covering the ends of the carpet and hard floor where they meet.
Lay the Z bar on the floor where the carpet meets the hard flooring. The flat side of the bar goes on top of the hard flooring and should be at least 3/8 inches from the tile edge to allow the carpet to be folded under the bar later. The side of the Z bar with the teeth goes toward the carpet.
Secure the Z bar to the floor, using a screwdriver and the screws provided. The Z bar has screw holes on the toothed side of the bar.
Cut the carpet underlay to the edge of the Z bar, using a utility knife.
Trim the carpet so that it is a half-inch longer than where it meets the tile. This will enable you to tuck the carpet into the Z bar later.
Pull the carpet toward you -- into the carpeted room -- so that the edge of the fold is just past the edge of the carpet side of the Z bar.
Lay the end of a mason's chisel on the centre of the carpet fold and hit the other end of the chisel with a hammer to push the folded carpet into the Z bar and under the edge.
Continue striking the chisel while moving to the left and then to the right of the centre until all of the folded carpet is under the Z bar.
Cut along the folded edge of the carpet that sticks out from under the Z bar to remove the excess not pushed under the bar. Don't cut the carpet beneath.
Hit the Z bar on the carpeted side using a beating block and a mallet to bend it toward the carpet. Don't strike with a lot of force. You only want to bend it slightly to secure the carpet to the strip of Z bar.