After the carpet is laid, it needs to be stretched in order to smooth out any wrinkles and take up any slack in the carpet. This is so that the carpet lies flat before trimming and tucking in the edges against the wall. The excess carpet at the edges needs to be folded up against the wall, and the corners need to be notched or cut so that the excess at the corners is not all bunched up. To stretch the carpet, you need to rent a knee kicker and a power stretcher.

Using the Knee Kicker

A knee kicker has a long handle with a toothed gripper at one end and a place at the other end to hit with your knee. To use the knee kicker, place the teeth of the gripper into a place in the carpet a few inches from the wall into which you want to "kick" the edge of the carpet. Then strike your bent knee forcefully into the other end of the knee kicker. This is a good way of forcing the carpet against the wall while still standing on it. Kick the corner of the carpet first, then the adjacent edges. After each kick, stretch the carpet against the wall directly opposite from the last kick.

Stretching the Carpet

A power stretcher is used to stretch the carpet. This rented tool has a power unit and a long series of tubing with a spiked gripper at one end a bar to fit into the kicked edge at the other end. Power stretchers with one spike were once used, but these tended to tear the carpet. More modern power stretchers have two or more spikes. The power unit forces the two ends of the tube toward the two walls and force the gripper end to kick the carpet into the wall opposite the edge of the carpet where the knee kicker was used. Power stretching the carpet should keep wrinkles at a minimum.

Finishing Off the Stretched Carpet

Knee kicking and power stretching should have stretched out all the wrinkles and taken up any slack. The place where the excess carpet makes a bend with the main body of the carpet should be forced into a sharp square edge into the junction of the floor and the wall. The excess can now be trimmed so that the edge of the carpet juts out from the outer edge of the tackless strip by about the height of the strip. Then the very edge is forced down into the gap between the wall and the tackless strip with a hammer and chisel or a carpet tucker.