Carpet strips are installed where your carpeting transitions to another surface. It may be wood, tile, metal, cement, or even other carpeting.
Start by measuring the length and width of the strip that you will require to cover the floor. When you go to purchase the strip, you will have to specify what kind of surface you will be transitioning to from the carpeted room. Different surfaces will have different thicknesses and hence different heights. Your strip will go from your type of carpeting to a thinner side designed to attach flush to the flooring on the other side.
Placing the Strips
After you have measured the correct sizing for your strip, mark it and cut it with a hack saw to fit in the space required. Now position the transition strip in the doorway with the teeth facing against the carpeted flooring. Make sure the strip is even and perfectly positioned on both sides and that it clears the doorway as well. Mark where you will screw it in. Drill starter holes and then screw in the carpet screws that came with the strip.
You can also install carpet strips for attaching the carpet and locking it into place. These are wood strips with nails coming out the top to which the carpeting attaches. These strips are usually sold in three foot lengths with the nails already installed. Measure the perimeter of the room to be carpeted and then cut strips down to fit on the ends. Lay the strips out around the room and nail them to the floor. Attach your carpet on one side of the room and the stretch it and attach it to the other side as well. If the carpeting continues through a doorway, have one strip on each side of the doorway. Be sure to buffer the baseboards of your wall so as not to damage them when nailing in the strips.