The most used stretching tool is called a knee-kicker. It is a simple, rod-like device that has a gripping surface at one end that sinks into the carpet and a padded bumper at the other end.
To use, get a grip on the carpet with the front end and bump the pad with a knee at the back end. Don't use this tool if you have physical problems with your knees. Even if your knees are fine, don't bump the pad too hard--it might cause an injury and could also tear the carpet if it is deteriorated.
Other types of stretchers are available, including power stretchers. All these tools are fairly expensive--even a simple knee-kicker costs $50 or more--so check with tool-rental agencies in your area to see if any are available to rent.
Additionally, check the condition of the tack strips that normally hold the carpet in place. The carpet might have pulled loose because one or more of these strips is damaged. The strips should be firmly fastened to the floor and have sharp prongs extending upward to grip the carpet. If any strips are damaged, you can buy new ones at some home centers and carpet-supply stores.
Tack strips usually come in 4-foot lengths. If you use a knee kicker, you want to pull the wrinkles out of the carpet so you can fasten it. Place the gripping pad at one end of the loose area so that it points toward the problem wall. Give the knee pad a thump so it moves the carpet toward the wall and starts pulling out the wrinkles.
Experiment with easy knee-thumps at first and don't build up force unless needed. Move the kicker about a foot each time, parallel to the wall, until you have flattened the carpet. You might need to move the kicker forward, closer to the wall, and repeat the series of knee thumps to get the carpet stretched enough to hook the edge on the tack strip.
The carpet should be flat and stretched enough so that you can tuck the edge down behind the tack strips. Force the carpet down onto the pointed strips with the end of a screwdriver; don't use your fingers or you might cut yourself. It's inadvisable for do-it-yourselfers to try and stretch carpet that is loose along more than one wall. It is time to call in an experienced carpet installer for that.--G.A.
RELATED ARTICLE: Finding the Right Padding
A firm and resilient carpet cushion is necessary to form a good foundation for any carpet, increasing its comfort and extending its life by acting as a shock absorber when someone walks on the carpet. The cushion, or pad, helps buffer sound and provides increased insulation.
When selecting a cushion, check the carpet manufacturer's requirements for thickness and density. Improper selection of carpet cushion can negatively affect carpet appearance, cause wrinkling and buckling, cause separation of the carpet seams and can cause a breakdown of the carpet structure itself. Improper cushion selection also may void any applicable carpet manufacturer's warranties.
A general rule of thumb for most residential carpet applications is to choose cushion no more than 7/16-inch thick and no less than 1/4 inch with 6 pounds per cubic-feet density. If the carpet is a Berber or a low profile carpet, choose a cushion no more than 3/8 inch thick with 8 pounds per feet density.--Carpet Cushion Council