Once you have selected your carpet and measured and prepped your stairs, you are ready to begin installing your new carpet. This article details how to install carpet on stairs, covering the full tread and riser (i.e., not a stair runner). However, if you are looking to install a carpet runner on your stairs, the following instructions can be modified accordingly.
Waterfall or French Cap
There are two basic methods of installing carpet on stairs: the waterfall method and the French cap method. The waterfall method involves bringing the carpet over the edge of the tread and essentially bringing it straight down to meet the next tread, without fastening it to the riser. It is a simpler and quicker method than doing French caps, but it does not provide as nice of a finish.
The French cap method wraps the carpet around the edge of the tread, contouring the nosing to meet the riser, then coming straight down the riser. It requires a bit more effort than doing a waterfall, but also provides a more professional appearance. These instructions provide information on installation using the French cap method.
How to Install Carpet on Stairs
Start at the bottom of the staircase and work your way up (unless your more difficult steps are at the bottom, in which case you may want to start with the easier ones to get the hang of it before moving on to the tricky ones). Before getting started, be sure to learn the terms for the different parts of your staircase. The instructions will be much easier to follow if you speak the same language.
Begin by stapling the carpet to the bottom riser. Be sure to work the nose of the stapler in between the fibers, so that a fiber doesn’t get caught under the staple and create a dimple in the carpet. If you do get a fiber caught, gently pull it out using a flat-head screwdriver. Do not pry it or pull too hard, or you could pull the fiber out as well.
The number of staples you use will depend on the carpet you are installing. Heavier, thicker carpets such as saxonies and thick berbers will require more staples than lighter varieties like friezes. Just be sure that the staples are distributed evenly across the riser.
Fasten the carpet underneath the nosing of the tread with staples, and wrap the carpet around the nosing and over the tack strip at the back of the tread. Using a knee kicker, stretch the carpet tight to the back of the tread, and hold in place until staples can be applied to the back of the tread behind the tack strip. Using the kicker, stretch also over the side tack strips (if against a wall) by positioning the kicker to face the side wall and stretching in that direction.
When the carpet is securely fastened, trim any excess. Repeat the process with the next riser. While the basic process will remain the same, the type of staircase you're working with will determine how you finish the installation. You'll want to determine if you have cap stairs, pie stairs, bullnoses, or Hollywood stairs.
If your stair is open on the side with railing posts, the installation will be a bit more difficult. The carpet must be cut around each post and re-joined on the other side. First, install the tread as described above. Next, make a slit directly in line with each post, to the edge of the carpet away from the stair. Wrap the carpet around each post. If you have larger wooden posts, you may have to trim some excess carpet around the base of each post.
Once you have brought the carpet around the posts, wrap it around the side of the stair and fasten it underneath the side nosing. To contour the 90-degree angle where the side of the stair meets the front of the stair, make a slit in the carpet diagonally from the corner to the outside of the carpet. The carpet will then be able to be folded over and brought together to cover the entire step.
If you have pie-shaped, or curved, stairs, there is not a lot that needs to be done differently to install the carpet. Install the carpet on the riser in the same way as mentioned above. For the tread, start as mentioned above by fastening the carpet to the floor under the nosing, and bring the carpet straight over the lip and across the tread. The only main difference is that there will be a lot more excess to trim.
You want the carpet on a curved stair to be straight off of the tread nosing; otherwise, it will look crooked when looking up the staircase from the bottom.
A stair that has a curved outside edge is referred to as a bullnose. It is found most commonly at the very bottom of the staircase as the first stair. The carpet can be wrapped around the curved lip of the stair by making a slit as was done for the cap stair, and flexing the carpet around the bend. Depending on the depth of the stair, you may need to make two or three slits to achieve the proper coverage.
Typically, carpet technicians install the riser of the bullnose separately from the tread to make it easier to wrap the carpet around the curve.
Stairs that have no risers are called Hollywood stairs. These are fairly simple to install; the same general process applies except the carpet is wrapped completely around the tread and stapled underneath.
The Bottom Line: Don't Rush
Installing carpet on stairs can be tricky and time-consuming, but it can be accomplished -- even by novices -- with some understanding and some patience. Don’t rush into it; be sure you know what is involved before you decide if you want to take the time required to do it or hire a professional.