How to Carpet Stairs: A Step-by-Step Guide

Choose an Installation Method

Before starting, it’s important to know that there are two primary methods of installing carpet on stairs: waterfall and upholstering (or sculpting). Knowing these two methods will dictate some of your measurements and how you perform certain steps. Note that both methods will work if your stairs have a nose (an overhang usually sticking out about 1 inch).

Waterfall

The waterfall method is one of the most common methods for carpeting stairs. With this method, when you wrap the carpet around a step, you let the carpet fall straight down to the next tread (the top/horizontal part of the step)—making it look like a tight 90-degree angle so you don’t see the overhead nose of the tread. This is the easier of the two methods and gives your staircase a casual look. For stairs without noses, you can only use this method. 

Upholstered (or Sculpted)

The upholstered, or sculpted method, is the other most common method for carpeting stairs. It is also known as the French Cap or Hollywood method. Instead of letting the carpet fall onto the next tread, you wrap it around the nose and staple it underneath with an electric tacker and 9/16-inch upholstery staples. 

Then, the carpet clings to the riser (the front/vertical part of the step) and falls onto the next tread. It is trickier than the waterfall method, as it requires some extra measurement and a bit more time and effort, but it can give an elegant flair to your staircase. This method can only work if your stairs have noses. 

Measure Your Stairs

Before you do anything else, especially before you purchase your carpet, you’ll want to measure your staircase, and anywhere else you want to install carpet. Doing so will inform how much carpet, padding, and tack strip you’ll need.

Measure the width of the tread to get the width of the carpet you need. Measure the length of the tread and the height of the riser, then add them together to get the length of each step. If your step has a nose, which sticks out over the riser, measure the top with the tread and the front with the riser. 

If you’re using the French Cap Method, measure the bottom of the nose and add it to the length of the step. Multiply the length of each step by the number of stairs to get the total length of the carpet you need. However, if each step is a different length, you’ll need to measure each separately and add the measurements together. Be sure to add an extra 10% to 15% to your total length; this way you’ll have some room for error. 

If your stairs have a landing, measure it separately from the other steps. Measure its width, tread length, and riser height. Add the total length of the landing to the total length of the staircase.

Purchase Your Carpet

Once you have the measurements, order the carpet. It’s easier to install carpet on stairs if you order it by the roll without seams and with even cuts. You’ll order your carpet rolls based on the length you need, and they come 12 feet wide. When figuring out how much carpet you need, first divide the width of the roll by the width of the stairs, which will give you the number of rows (rounding down) that you’ll be able to get from the roll. 

Then, divide the total length of the staircase (including the extra 10% to 15%) by how many rows you have, giving you the total length of the carpet roll you should get. 

For example, let’s say your staircase has 15 steps, which are 3.6 feet wide and 2 feet long. Divide 12 by 3.6 to get 3.33, which means you’ll get three rows of carpet out of a roll when rounded down. Then, multiply 2 feet by 15 stairs to get a total length of 30 feet. Finally, divide 30 by 3 to get 10; thus, your carpet should be 10 feet long, adding an extra foot or foot and half for the extra carpet.

Prep the Stairs for Installation

If you’re replacing carpet on stairs, remove all the carpet and padding using a pair of pliers and a utility knife. You may find that the difficulty varies; sometimes, the old carpet will pull out easily, while other times, it’s stapled in so deeply that it requires a lot of elbow grease to remove. 

Once all the old carpet is gone, remove the padding on the tread, though sometimes it's also on the riser, depending on the method used to install the original carpet. Remove padding by pulling it off from the corner. Then, use a floor scraper to remove all of the staples. If you’re having trouble, use pliers to pull them out. 

Pulling out tack strips isn’t always necessary if you’re installing carpet on stairs. Usually, you only have to remove tack strips if they’re significantly damaged, moldy, or loose. However, depending on your installation method, you may need tack strips in different places, so remove them accordingly. 

Use a molding lifter to remove tack strips, pulling up from underneath each strip. Finally, sweep and vacuum the stairs with a wet-dry vacuum to ensure they’re clean and ready for installation. The previous steps aren’t necessary if the stairs were already bare and clean.

Lay Down the Tack Strips

This step is only necessary if you need to replace tack strips or if you need to install carpet on a brand-new set of stairs. First, measure how much tack strip you need based on the width of the tread and riser. You need at least one strip, going wall to wall, near the back of the tread, leaving a gap behind the strip. This gap is usually twice the thickness of the carpet.

You may also need a strip near the bottom of the riser, but only if you're using the waterfall method. You can also put a strip on each side of the tread, leaving about a 1/4-inch gap from the wall, especially if you’re upholstering your stairs. Additionally, if the carpet backing is stiff or your pad is extremely thick, you may consider using two tack strips for each placement. 

Cut the pieces you need with a tack strip cutter or a pair of metal nippers and put them in place. Remember that the tacks that hold the carpet on a strip lean in one direction, so when putting them down, make sure they’re pointing toward the wall or riser.

Tack strips usually come with nails embedded in them; ideally, use tack strips with extra long nails. Ensure they aren’t concrete nails, which can easily come loose later. Next, hammer the strips into the treads or risers. If your strip doesn’t have nails or you need some backup, use an electric tacker to put in a 9/16-upholstery staple or a 1-inch nail every 2 to 3 inches.

Lay Down the Padding

With the tack strip down, measure the width of the stairs and cut your carpet pad to match the width. If you’re using the waterfall method, first staple the pad in the back of the tread, in front of the tack strip. Then, pull the pad over the edge and down as close to the tack strip as possible to get a snug fit but not so hard you pull the staples out. Then, staple a row on the pad along the bottom of the riser. Use a utility knife to cut along the tack strip to remove any excess padding.

If you're upholstering your stairs, you only need a pad on your tread. Make sure the pad is cleanly cut along the front of the tread and staple it along the front. Then, pull the pad toward the tack strip on the back of the tread and staple the pad down along the back, in front of the strip. Use a utility knife to remove any excess padding.

Repeat this for every step in your staircase. If your pad starts to bubble, staple it down.

Measure and Cut the Carpet

With the padding and tack strips down, you can finally start with the carpet. Roll out your carpet and measure it, making sure you have enough. Cut off the selvage edge by about 1 inch. The selvage edge is a woven border running lengthwise on the edge of the carpet that keeps the carpet from fraying on the sides, but it can hinder the installation if you don’t cut it off. 

There are a couple of ways to cut the carpet. You can use a straightedge and a knife. If you cut on top of the carpet, use a utility knife—but if you cut on the back, use a carpet knife (it’s a knife with a two-sided blade, so be careful). You’ll need to cut certain carpets from the back, like a plush carpet. 

To be more precise, you can use a row cutter and a narrow nail set. Use the nail set to separate the carpet fibers, leaving a straight, impermanent line in the carpet. Then, use the row cutter to follow along the line. However, this method will only work on top of the carpet and on certain types of carpet, usually loop-pile carpets, commercial carpets, and Berbers. 

Before you cut, be sure to measure out exactly what you need and cut accordingly. If your carpet is thick, cut it short by about 1/8 inch. The carpet fibers should cover the edge, and you can stretch it if you have a tack strip on the side. Ensure your cuts are clean and straight lengthwise. You can install carpet on each step individually, or you may want to install it across multiple steps with one long run of carpet.

Lay Down Your Carpet

Lay the carpet along the staircase, ensuring everything is properly aligned.

For an easier installation, make sure your carpet is warm, whether from being in a warm house or sitting out in the sun. Depending on the type of carpet, it may be more difficult to install; thicker and heavier carpets like wool are usually harder to install, while softer carpets like polyester are usually easier.

Start at the Bottom of the Staircase

Start at the bottom step of the staircase. Use your stair tool to tuck your carpet underneath the bottom riser. To make sure your carpet is properly aligned, cut the end of the carpet square with the width of the stairs. 

If you’ve finished one run of carpet and are starting another on the next step, treat it like it’s the bottom step; this also applies if you're installing carpet on each step individually, treating every step like the bottom one. By the end, it should be indistinguishable from where you started and where the row stops.

Adhere or Staple Your Carpet

Next, you want to ensure that the carpet sticks to the bottom of the riser. If you’re using the waterfall method, use the face of a hammer to rub along the tack strip underneath the carpet. Doing this will bend the nails into the backing of the carpet. You can also lightly tap across the tack strip to bend the nails.

If you’re upholstering your staircase, use your electric tacker to staple 9/16-inch upholstery staples in the carpet along the bottom of the riser. Next, make sure the carpet is snug around the nose of the tread. Then, use the electric tacker to staple the carpet underneath the nose.

When stapling, staple once in the center of the row and do the rest going from wall to wall. Double tapping for each staple may lead to a better result. Stapling between threads of the carpet will minimize dimpling. You only have to do this on the riser, as no one will see under the nose.

Kick in Your Carpet

Go onto the next tread and place your knee kicker in the center, right in front of the tack strip. Fully extend your knee kicker and be sure the teeth are firmly in the carpet—going through to the secondary backing, or you may shred the carpet fibers off the primary backing. Knee into the pad of the knee kicker to kick your carpet in toward the riser, which stretches the backing of the carpet into the tack strip. Hold on tightly to the knee kicker while you do it, and work your way out from the center on both sides until the carpet adheres to the tack strip.

Crease Your Carpet

Crease the carpet by tucking your stair tool in where the riser meets the tread and hammering it in. Hit the stair tool with the hammer two to three times all across the stairs, going from wall to wall. This will tuck the carpet on the tread under the riser while also tucking the carpet on the riser in with it. If you’re at the end of the run, use this step to tuck the end of the run under the riser. Then, go back to step seven for the beginning of the next run.

Finishing Touches

Repeat steps seven through 10 as needed until you reach the top stair. 

If your carpet at the top of the stairs differs from the one you’re installing on the steps, then you want to ensure the material upstairs goes around the nose on the top floor, if there is one. Even if there isn’t, you don’t need padding or tack strips on the riser. Pull the carpet up the riser and use your electric tacker to staple the carpet along the top of the riser. Make sure your carpet is cut squarely under the nose or on the edge of the top floor tread. 

If you have tack strips on the sides of the treads, go back down and knee-kick the carpet into them. With tack strips on both sides of the tread, you can stretch your carpet if you get wrinkles.