Leave three to five inches of wood showing on each side, pick a low dense pile, and if your staircase turns, be careful with patterns. That covers most of it. The rest is detail worth getting right, because a staircase is the most looked at surface in a house and the hardest one to redo.
Getting the width right
A stair runner should be narrower than the tread, with an even reveal of finished wood on both sides. Three to five inches per side is the range that looks deliberate. Less than three and it reads as a wall to wall install that came up short. More than five and the runner starts to look skinny.
On a standard 36 inch staircase, a 27 inch runner leaves four and a half inches on each side. That is the safe default.
Measure at the narrowest step. Older Pittsburgh staircases are frequently not consistent top to bottom, and the runner has to fit the tightest one.
If your treads are already finished on the outer edges, that finished portion tells you the width the original builder intended, which is often the right answer.
Waterfall or cap and band
These are the two ways a runner meets the front edge of a step.
Waterfall lets the carpet flow from the nosing straight down to the next tread without being pulled into the corner where riser meets tread. It is simpler, faster, and cheaper, and it suits a casual or modern staircase. The step edges look softer and less defined.
Cap and band, sometimes called French cap or upholstered, wraps the carpet tightly around the nosing and pushes it into the corner so the profile of each step shows through. It looks sharper and more tailored, and it is what you see on traditional and period staircases. It takes noticeably longer to install and costs more.
Neither is more durable. Choose based on the staircase. Ornate newel post and turned balusters, go cap and band. Simple painted stringer and a straight run, waterfall is fine and honest.
One caveat: strongly patterned runners generally look better cap and band, because the pattern stays aligned with the step. On a waterfall the pattern drops over the nosing and can look like it slipped.
Patterns, and the problem with turns
A patterned runner on a straight flight is straightforward. The installer keeps the pattern centered and square as it climbs, and it looks great.
A patterned runner on a staircase with winders (the pie-shaped steps on a turn) is a different job. Each winder is a different shape, and keeping a stripe or a geometric square on a wedge means cutting and fitting every one individually, sometimes with a seam. It can be done beautifully. It takes time and it costs more.
If your staircase turns and you want to keep things simple, a solid color, a subtle tonal texture, or a small allover pattern with no strong directional line will save you money and still look intentional.
Stripes running up the stairs (with the direction of travel) handle turns better than stripes running across.
Fiber, honestly
Stairs take more abuse per square foot than anything else in a house, and it is concentrated on the nosing.
Nylon is the best all-round choice. It has the strongest crush and abrasion resistance, which is exactly the property a stair nosing needs. It costs more than polyester and it is worth it here.
Wool is the traditional stair runner material and it is excellent. Naturally resilient, ages well, holds color. It is the most expensive option and it can shed for the first few months.
Polyester is soft and inexpensive. It is fine on a lightly used staircase, less so on the main stairs of a busy house. It will flatten at the nosing before nylon does.
Triexta sits between polyester and nylon on both price and resilience, and it cleans well.
On construction, go low and dense. A tight level loop or a low cut pile survives stairs. A long shag or a loose loop does not, and a loose loop plus a dog is a guaranteed pulled row.
Test any sample by folding it backward. If the backing grins through, it is not dense enough for stairs.
Colors that survive real life
Mid-tone patterns and textures hide traffic. Solid pale colors show every footprint on the nosing, and solid dark colors show lint and dust.
The nosing is where wear shows first, so a carpet with some visual texture buys you years of looking clean.
If you have a dog, keep the color somewhere near the color of the dog. It is unglamorous advice and it works.
Padding on stairs
Yes, you want it. Stair pad should be firm rather than plush, because a soft pad lets the carpet move under the nosing and accelerates wear right where you cannot afford it.
Pad on stairs is cut into individual pieces per step rather than run continuously, and it stops short of the nosing so the carpet can wrap tightly.
What the install is worth
More on stairs than anywhere else in the house.
A staircase is dozens of individual fitted pieces, each one visible from the room below. Even nosings, tight corners, a straight climb, matching reveal on both sides: that is craft, and it is the difference between a runner that looks custom and one that looks like a rug someone stapled down.
Ask who is doing the work, and ask how long they have been doing stairs specifically.
At Remnant City the person who measures your staircase is the person who installs it, and the same installer comes back if you ever need anything. We have been on Route 51 since 1970, and stairs are a big part of what we do. Our project gallery is mostly real stair jobs in real Pittsburgh houses, photographed after install rather than staged.
Getting a number
Count your steps, note whether there are winders or a landing, and measure the width of the narrowest tread. Call (412) 885-1444 with that, or send it through the site.
If you are also carpeting the basement steps, our guide to basement stairs and risers covers what to do before the carpet goes down.
