Guide · For the trade
Stair nosing carpet: specifying commercial stair carpet and the nosing that finishes it
Stair nosing carpet on a commercial stair is a dense, low-pile carpet at 1/4 inch or under, glued direct to the tread and riser or installed as carpet tile, finished at each step edge with a nosing: an extruded aluminum or rubber profile with an undercut lip that the carpet tucks under, a slip-resistant insert on the walking face, and a contrasting color where the code wants the step edge read. The nosing protects the edge the carpet cannot, and the two are specified together, with the carpet's thickness matched to the nosing's gauge.
This guide is for the designer or the junior specifying carpet for commercial stairs: an office, a hotel, a school, a multifamily corridor stair. It covers why a commercial stair takes a nosing, the nosing types and how to match them to carpet, the carpet itself, the code points, what to write for the installer, and the questions clients ask. The residential stair, with pad and runner, is in the best carpet for stairs guide.
Why a commercial stair takes a nosing
A residential stair is carpeted over a pad, stretched and wrapped around the nosing, and the carpet itself is the step edge. On a commercial stair that edge sees hundreds of feet a day landing on the same 2 inches of carpet, plus carts, luggage and cleaning equipment. A wrapped edge wears through in two to four years and becomes a slip hazard. A nosing moves the wear point onto a metal or rubber profile that lasts the life of the building, gives the foot a slip-resistant surface where it matters, and lets the carpet be glued flat on tread and riser. It also makes the edge visible, which the IBC and the ADA both treat as a safety element.
Stair nosing types for carpet
| Nosing | What it is | Carpet it suits | Specify it for |
|---|---|---|---|
| Aluminum with abrasive insert | Extruded aluminum angle, 1 1/2 to 3 in face, abrasive strip in the walking face, undercut lip for the carpet | Glue-down broadloom and carpet tile at 1/4 to 3/8 in | Exit stairs, exterior and high-traffic stairs, anywhere wet |
| Aluminum with vinyl or rubber insert | Same profile with a colored vinyl or rubber insert; quieter, contrast colors | Glue-down broadloom and carpet tile | Office, hotel and school stairs where the look matters |
| Rubber or vinyl undercut nosing | Flexible one-piece profile, 1/4 in undercut, glued to the step edge | Carpet tile and low broadloom at 1/4 in | Multifamily corridors, schools, budget-led projects |
| Carpet nosing with return | Metal profile that wraps a projecting nosing and returns under it; carpet butts to it on tread and riser | Broadloom on a stair with a bullnose | Renovations |
The matching rule is the gauge: an undercut nosing is made for a stated carpet thickness, 1/4 inch for most carpet tile and dense loop, 3/8 inch for a heavier broadloom, and the carpet has to be that thickness or the lip stands proud and trips. Put the carpet's total thickness from the spec sheet on the nosing line of the order.
The carpet for commercial stairs
A dense loop or a tight cut pile in solution-dyed nylon, 20 to 28 oz, pile height 1/4 inch or less, with a backing suited to direct glue-down, is the standard. Woven wool-nylon Wiltons and Axminsters at 40 oz and up are the hospitality version, glued direct or over a thin dense pad where the stair is not an exit stair. Carpet tile on stairs works on a straight commercial stair: the tread tile is cut to the tread depth and the riser tile to the riser, each glued, and the undercut nosing covers both cuts, so a worn tread is a single tile to replace. No pad except under the hospitality Wilton, and then 1/4 inch slab rubber at most; a cushioned stair under a nosing flexes at the lip and loosens it. A small all-over pattern or a heather hides the wear path; a pale solid shows it in a month. Masland's solution-dyed nylon loops and Milliken's nylon patterns, both with Class I ratings and Green Label Plus certificates, are the light-commercial starting points in our library; heavier commercial lines are quoted by project.
The code points behind the spec
The numbers to check with the project's code consultant, because jurisdictions amend them. The ADA limits the nosing radius to 1/2 inch and the projection to 1 1/2 inches, and requires carpet on an accessible route to be firmly attached with a pile of 1/2 inch or less and exposed edges fastened and trimmed. The IBC sets the nosing projection at 3/4 to 1 1/4 inches on treads under 11 inches, the radius at 9/16 inch maximum, and riser and tread uniformity within 3/8 inch across the flight, so every step gets the same nosing. The IBC also sets flame spread: an enclosed exit stair needs Class II under ASTM E648 in most occupancies and Class I in healthcare and institutional ones, and the simple answer is Class I, 0.45 W/cm2 or more, on every commercial stair. Some jurisdictions, California among them, require a 2 to 4 inch contrasting stripe at the nose of each tread in public buildings, which a colored nosing insert satisfies. The ADA carpet guide and the carpet fire rating guide go further.
What to write for the installer
- Stair count, tread and riser dimensions, and whether the existing nosing projects or is flush.
- Carpet by style, color and total thickness, with the installation method (direct glue or tile) and the adhesive.
- Nosing by profile, face width, insert type and color, and gauge matched to the carpet thickness.
- Pattern direction on tread and riser, and where any seam falls (under the nosing lip, never mid-tread).
- Landings, glued the same as the treads, with a transition strip at any change of material.
- Open sides: where the carpet stops and how the edge is bound or capped.
Our installer network handles commercial stairs anywhere in the country, and the nosing can be sourced with the carpet.
Questions designers ask
Does a carpeted commercial stair need a nosing?
Yes, on any stair with public or employee traffic. The nosing takes the wear the carpet cannot, keeps the step edge visible and slip-resistant, and is the practical way to meet the code's edge requirements. A light-commercial stair in a small office can be wrapped like a residential one.
Rubber or metal stair nosing for carpet?
Rubber or vinyl for a quieter, lower-cost stair in a corridor, a school or an apartment building. Aluminum with an abrasive insert for an exit, exterior or heavy-traffic stair, and aluminum with a vinyl insert when the stair is seen. Both come in contrast colors.
What nosing goes with carpet tile on stairs?
An undercut nosing at the tile's gauge, usually 1/4 inch, in rubber, vinyl or aluminum. The tread tile tucks under the lip and the riser tile butts to the nosing's return. Order the nosing with the tile so the gauge is confirmed.
What is the best non-slip carpet for commercial stairs?
A dense solution-dyed nylon loop at 1/4 inch or less, glued direct, under a nosing with a slip-resistant insert. The carpet is never the slip resistance on a commercial stair; the nosing is.
What fixes a slippery carpeted stair in an existing building?
A retrofit undercut nosing glued over the wrapped edge, or a replacement with a glue-down carpet at 1/4 inch and a new nosing. Non-slip strips stuck to the carpet are a maintenance item, not a spec.
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