Before the tack strip made the job easier, carpet was installed to stairs with glue and tacks. This old method was replaced by the tack strip because the older method was not as durable as installation teams desired. Tack strips hold the carpet into place and prevent glue from loosening, carpet from sagging and avoid the placement of tacks in traffic zones. Tack strips are the best method to install carpet on stairs, but you can install carpet on stairs without a tack strip to make removal of the carpet easier if you plan to replace the carpet soon.
Measure the treads of each stair step to place carpet on each tread. Measure the entire width and all of the length if you want to completely cover the tread; measure a portion of the stair if you want to center the carpet on each step.
Cut the pieces of carpet out with a utility knife. Rectangle shapes are common for carpeted stair treads, covering all of most of the stairs, though other shapes such as trapezoids may also be used for the stair covering.
Work from the top of the stairs to the base, attaching carpet to each stair tread. Apply carpet glue to the back of the carpet sections and attach the carpet to the tread.
Load the nail gun with short, thin tacks. Pull back the carpet fibers along the edges of the carpet pieces and place the firing end of the nail gun as close to the base of the carpet as possible before pulling the nail gun trigger. Continue this process every 2 inches along the outer edge of the carpet pieces on each tread
Set the tacks further into the carpet to prevent minor injuries to bare feet. Place the nail set over the tack heads and use the tack hammer to pound the other end of the nail set and sink the tack heads further into the carpet.