How to Install & Measure a Carpet Runner on L-Stairs

Measure the width of the carpet runner. Subtract 2 inches from the width to get the width your tackless carpet strips should be. Count the number of stairs in the L-shaped staircase and cut a tackless carpet strip of this width for each stair.

Measure the width of a stair in the staircase. Subtract the width of one of the tackless carpet strips you cut. Divide this number by two to get how far in from each side of the stair the tackless carpet strip should sit, and secure a strip in place at the back corner of each stair by hammering the nails in the tackless into the stair.

Start at the top of the first section of the L-shaped stairs. Measure back along the landing or the hallway at the top of the stairs to the opposite end of the landing or hallway. Note this distance.

Measure the height of the top stair and then measure the depth of the stair from the back to the front. If the stair has a front edge that juts out, make sure to include this part of the stair when measuring. Add the height and depth of the stair together and multiply the product by the number of stairs in the top section.

Measure the landing at the bottom of the first section of the L-shaped stairs from the edge of the bottom stair to the spot on the landing where you want the runner to end. Add this measurement to the total measurement for the stairs and the measurement you took at the top of the stairs. Cut a carpet pad down to the length of this sum, then cut the carpet pad lengthwise to the same width as the tackless strips you placed on the stairs.

Measure each section of the L-shaped stairs using this same procedure. On the bottom section, measure out from the bottom of the staircase the distance across the floor that you want the carpet runner to extend from the stairs, just as you did for the top landing. Add the floor measurement to the total measurement of all of the stairs in the bottom section and cut a carpet pad down to this total length.

Lay each section of carpet pad that you cut on the corresponding sections' stairs. On each stair, push the carpet pad back so it snags the tackless strips, then place a staple along the front of the pad along the front edge of each stair.

Cut a carpet runner strip for each separate section that you measured on the stairs. Make each strip a foot longer than the total measurement of the section to make sure you have enough to cover the entire expanse.

Start at the top of each section of the L-shaped stairs and center the carpet runner over the carpet pads in each section so that the edges hang over the sides of the pad by an equal amount. Press the carpet runner back into the back corner of each stair. Place a knee kicker at one side of the carpet runner on the stair, press the kicker forward, then continue across the stair in this manner until the entire runner clings to the tackless strip. If you get to the end of a section and have excess carpet, use a utility knife to cut the extra away.

Smooth the runner out over each stair, fold the runner over the edge of the stair and staple the runner at the top of the back part of the stair, just beneath the tread of the stair -- the part you walk on. For each section of the L stairs, start at the top and work your way down the stairs, cutting away any extra at the bottom. On the landings, butt the edges of the runner against each other where they meet and apply carpet tape to the seams to hold the runner edges together.