A carpeted stairway quiets your home by softening footsteps and absorbing sound waves. Carpeted stairs are safer than hard-surface stairs, as they lessen your chances of slipping and pad your fall if you lose your balance.
Building codes control the dimensions of treads and risers. Treads are typically 10 to 11-1/2 inches deep; the deeper the tread, the more comfortable the climb. Risers are generally no more than 7-3/4 inches tall. If your stairs dimensions are not within these guidelines, for safety's sake you'll need to rebuild them.
Stairways get heavy wear, especially along the tread nosing, so choose a carpet that is durable and easy to clean. A carpet with an attached padded backing is easier to put down, but these carpets are not usually recommended for stairways as they have a tendency to wear quickly.
Measure each step individually and cut a quality carpet pad to fit each step and riser as shown. The pad should be cut to precisely fit between the tackless strips that you'll be nailing to the back of the tread and the bottom of the riser.
If your staircase curves or if the walls are not plumb, you won't be able to use a template to cut the carpet pieces for each step. Instead you'll need to measure each step and cut the carpet to fit.
Carefully place tackless strips on the riser and back of each tread as shown. To determine how high to place the tack strips, use a spacer made out of two strips taped together.
Make a spacer by taping two tack strips together. This will help you properly position your tackless strips.
Using a hammer stapler and starting in the center of each stair tread, staple the carpet pad in place. Staple across the entire length of the pad. (Staple the pad just in front of the tackless strip.)
Wrap the carpet pad around the front edge of the steps and down the riser. Smooth and stretch the pad so that it fits tightly against both the tread and riser, then staple pad to riser. When all the padding is attached you'll need to make a template and cut the carpet to fit.
Using a tape measure, measure the stair and riser and add 4 to 6 inches (or more if your steps are deeper) to the stair width to cover the edges.
To make the template, measure each individual step and riser, as they may not all be built to the exact same dimension. Using a tape measure and a straightedge, cut the carpet to template size.
Center the carpet on the bottom edge of the steps. Use an awl to push the carpet onto the tackless strip. This creates a clean line between the bottom of the stairs and the flooring.
When you are satisified with the carpet placement, staple the carpet onto the riser just below the tread taking care not to staple through the fold. Wiggle the electric carpet tacker between the nap to hide the staple impressions.
Using a knee kicker, stretch the carpet into the seam between the tread and the riser. Start in the middle and work side to side.
Fold the edges around the step and use a stair tool and a rubber mallet to crease the carpet into the seam and secure it to the tackless strip. Repeat Steps 8 through 11 for each remaining step.