One of the great things about wall-to-wall carpeting is that its surface is completely smooth and wrinkle-free. If you’ve ever watched carpet being installed, you know that it didn’t get flat on its own–the installers had to wrestle it into its state of repose with special stretching tools.

Carpet Stretching Tools

The two main tools are the aptly named power stretcher and the knee kicker. Both have flat, aluminum heads that are fitted with rows of adjustable steel teeth, angled forward so they can better bite into the carpet.

Knee Kicker

A knee kicker is about 20 inches long, with a square toothy head on one end and an equally-sized knee pad at the opposite end.

Power Stretcher

A power stretcher has a larger rectangular head, usually about 15 inches wide, that’s connected by a spring-loaded lever to a series of telescoping tubes that terminate in a padded block.

Depending on the model, the tubes can be extended up to nearly 40 feet in length so that the stretcher can bear against the opposite wall. A good-quality kicker costs less than $100, but power stretchers start at around $500. So unless you’re going into the carpet business, it makes sense to rent, rather than buy. Here’s how to use them:

Steps for Stretching Carpet

When you’re installing new carpet, the first thing you’ll need to do is nail tack strips around the perimeter of the room.

Tack strips resemble old-fashioned wooden yardsticks pre-nailed with small, very sharp pins. These strips bite into the carpet and keep it in place.

Leave a space of a couple of inches between the strip and the wall. Install the carpet pad, which should cover the floor within the boundary established by the tack strips. Use a hammer tacker to staple down the pad, then you can roll out the carpet.

The first carpet stretching tool you’ll use is the knee kicker.

1. First, check the depth of the teeth—when the head is pressed down on the carpet, the teeth should bite into the pile and backing, but not protrude through it. You can use the dial on the kicker’s head to adjust the depth of the teeth.
2. Starting in one corner, press the kicker head firmly into the carpet a few inches away from the tack strip, and use your knee to strike the kicker’s padded end.
3. Maintain pressure on the kicker and press the edge of the carpet down onto the tack strip, making sure to leave some excess carpet against the wall that you can later trim at the baseboard.
4. Repeat these steps along the same wall until the carpet is taut.
5. With the carpet in place along the first wall, assemble and adjust the power stretcher so that its head is a few inches opposite from the first wall and the padded tail block is placed against the first wall’s baseboard.
6. Press the head’s teeth into the carpet, again checking that the teeth are adjusted to the correct length.
7. Now engage the mechanism by pulling back on the level, which will push the carpet toward the second wall. Keep an eye on the lever’s adjustable tension; too much tension can damage the carpet and not enough will leave slack.
8. Press the carpet down into the tack strip to lock it in place and move the assembly to the next section of carpet.
9. When the carpet is stretched toward the second wall, use the knee kicker to attach the carpet on the next perpendicular wall and stretch it to the final wall with the power stretcher.
10. Once the carpeting has been successfully stretched across the room, use a curved carpet knife or sharp utility knife to trim the edges.
11. Using one hand to press the carpet down into the intersection of the baseboard and floor, cut away the excess with the knife. If your rental center has one, you can use a specialized carpet edging tool instead of a knife to make clean cuts against the baseboard. At this point, it’s handy to have a stair tool, which has a heavy, wide steel blade. Installers use stair tools to wedge the trimmed carpet down into the crevice between the tack strip and the baseboard.

Put New Life into Older Carpets

These same stretching tools can be used to work their magic on older wall-to-wall carpeting that has developed loose spots and ripples.

• Start by peeling the carpet from the perimeter tack strips. If the tack strips are rotting due to water damage or have lost their grip because they’ve been pounded down from foot traffic, it may be necessary to replace them with new strips.
• Roll the carpet back into place, and, using a knee kicker, lock down the carpet along the first wall, then continue the process with the power stretcher.