Gluing carpet onto stairs will prevent wrinkles and loose carpeting from developing bumps across the stair treads. However, glue should never be used alone to install carpeting on a staircase. It should be used with other fasteners to hold the carpet more securely into place. Applying the glue is a simple process that will hold the carpet while you attach it more firmly.
Place the tackless strips at the back of each stair tread and at the bottom of each stair riser. The strips must sit 1/2 inch from the corner where the back of the tread meets the bottom of a riser. The tackless strips can be stapled into place with the staple gun. They provide a secure carpet fitting to protect against the glue coming loose.
Measure the carpet for the stairs. Measure the tread width and the overall length of the staircase. If you are draping the carpet roll over each stair tread and riser, measure accordingly. If you are only placing the carpet on stair treads, only measure the depths and widths of each stair tread.
Cut the carpet into single tread pieces or one large piece to drape over the entire staircase, using the utility knife. Roll the carpet inward so the top of the carpet faces inside the roll. Work from the top of the stairs to the bottom, unrolling the carpet as you move down.
Hook the carpet into the tackless strip at the top of the stairs. Apply glue to the stair riser (if applicable) and the tread, using the glue trowel. Stretch and pull the carpet down onto the glue to eliminate wrinkles. Secure the carpet onto the next tackless strip as you move down the stairs.
Continue applying glue between the tackless strips, pulling the carpet taut over the glue and securing it onto the next strips until you reach the final strip. Allow the glue to dry for 24 hours. Trim the edges of the carpet with the utility knife. Place staples every 2 inches along the outer edges of the carpet to further secure the carpet to the stairs.
Cleaning the stairs thoroughly and setting any nail heads will prevent the carpet from wearing out in spots where debris was left before installation.