---
title: Stair Parts and Railing Vocabulary
description: "On this page[Introduction](#)[Before You Begin](#)[Prerequisites](#)[What You Need To Know](#)[Tread, Riser, Nosing: the Basics and the IRC Numbers That Size Them](#)[Stringers: Cut vs Housed, and the Skirt Board](#)[Newel Posts: Box, Turned, Half, Pin-Top, Starting, and Landing](#)[Balustrade Systems: Post-to-Post vs Over-the-Post, and…"
url: "https://letsbuildstuff.co/learn/stair-parts-and-railing-vocabulary/"
updated: "2026-10-09"
category: Stairs/Handrails
---

# Stair Parts and Railing Vocabulary

On this page[Introduction](#)[Before You Begin](#)[Prerequisites](#)[What You Need To Know](#)[Tread, Riser, Nosing: the Basics and the IRC Numbers That Size Them](#)[Stringers: Cut vs Housed, and the Skirt Board](#)[Newel Posts: Box, Turned, Half, Pin-Top, Starting, and Landing](#)[Balustrade Systems: Post-to-Post vs Over-the-Post, and Why the Newel Type Comes First](#)[Handrail: Plowed vs Unplowed, Shoe Rail and Fillet](#)[Handrail Profile Numbers, and the Graspable-Rail Code (Type I and Type II)](#)[Fittings: Volute, Turnout, Easing, Gooseneck, Quarterturn, Rail Bolt, and Rosette](#)[Balusters: Wood and Iron Stock Sizes, Pin-Top vs Square-Top](#)[False Tread, Return Nosing, Landing Tread, and the Bullnose Starting Step](#)[Guard Height and Baluster Spacing: the Code Numbers, and the House Number Beside Them](#)[Wall Rail, Rail Brackets, and Wall Cap](#)[Stair-Part Species, and the "Breadloaf Rail"](#)[Stair Parts Quick Reference](#)[Related Guides](#)

[Stairs/Handrails](/learn-category/stairs-handrails/) Skill Level: [Intermediate (Level 2)](/learn/difficulty-levels/#level-2) · Estimated Time: 35 Minutes To Read

## Introduction

Stair parts carry two meanings half the time, depending on whether you mean the stair itself or the railing on top of it. The code numbers quoted throughout come from [IRC Chapter 3](https://codes.iccsafe.org/content/IRC2021P2/chapter-3-building-planning).

Stair parts get more confusing than almost anything else in this trade, because many of the words carry two meanings depending on whether you are inside the house or outside it, and the rest get used loosely on a jobsite text when the correct name would have taken three seconds to type. A [handrail](/learn/mount-handrail-wall/) is not a guardrail. A stair cap is a false tread. A [rosette](/glossary/moldings/#rosette) on a staircase is not the same part as a rosette on a [door casing](/learn/install-exterior-door-casing/). This guide sorts every one of those pairs out, in the order a stair goes together: tread and riser first, then the stringer and skirt board under them, then the newel posts and rail system on top, then the fittings, balusters, and small parts that finish it off.

This is a vocabulary guide, not a build sequence. Most parts below point to the guide that covers installing them; a few, like the plow in a handrail, a starting newel, or a rosette, do not have their own guide and get defined here in full. Separate guides in this series cover [S4S](/glossary/materials/#s4s-surfaced-four-sides) and [nominal versus actual sizing](/glossary/materials/#nominal-vs-actual-size), [base shoe](/learn/install-base-shoe/) as a profile and the mitered return as a technique, how to tell one stair-part species from another, and stair stringers on a slab and the treated-lumber question. This guide points at each instead of repeating it, and adds only what is specific to stairs and rails.

## Before You Begin

### Prerequisites

You do not need any tools to read this guide. If you want to check a term against real material, grab a stair tread cutoff, a scrap of [skirt board](/learn/install-skirt-boards/), and a rail offcut if the truck has one. Holding the actual part while you read the name fixes it faster than the page alone.

### What You Need To Know

This crew builds a staircase in one order, and knowing it tells you which guide covers which part: skirts, then nosing, then [newel posts](/learn/install-newel-post/), then the rail with every baluster hole drilled, then the wall-mount [handrail](/glossary/stairs/#handrail), which can land any time and which this crew does last, in case rail material runs short. Balusters themselves wait for a separate trip, covered under Balusters below.

Most parts in this guide sit in one of four places.

- **The rough stair.** What the framer builds: the stringer, and the rough tread and riser it carries.
- **The finish stair.** The skirt board, the wood nosing, and the finished riser, all applied trim over that framing.
- **The rail system.** Newel posts, the handrail itself, its fittings, and the balusters or other infill that stands inside the guard.
- **Small finish parts.** The false tread, the return nosing, and the wall cap at a knee wall.

Keep two pairs of words apart as you read. Inside the house, riser means a finish board the painters finish to match the job; on a garage or patio step outside, the same word means a structural board or an open gap, a different trade entirely that this guide only points at once. And a handrail is not a guardrail: a handrail is for grabbing, a guardrail stops a fall and carries the balusters or bars, and the rail on an open stair usually does both jobs at once, which is exactly why this guide keeps the two words, and their sections, apart.

## Tread, Riser, Nosing: the Basics and the IRC Numbers That Size Them

A [tread](/glossary/stairs/#tread) is the board you step on, measured from its front edge, the nosing, back to the riser behind it. Inside the house, a [riser](/glossary/stairs/#riser) is the finish board on the vertical face between two treads, painted or stained applied trim, the only sense this word carries here; this crew also uses "riser" for a structural, exterior sense on a garage or patio step, a different trade [a separate guide in this series](/learn/exterior-trim-materials/) covers. Everywhere below, a riser on this crew's jobs is always closed, never open, and a finished riser goes in only where the stair gets a hard-surface finish, LVP or wood treads, never carpet.

The [nosing](/glossary/stairs/#nosing-return-nosing) is the tread's front overhang past the riser below it; [How to Install Wood Nosing](/learn/install-wood-nosing/), as published, covers that piece and names oak or maple as the usual stock. This crew uses the same word for an unrelated second part: a 1x8 S4S board laid on a ledge on a flat run, the base the rail sits on before the newel posts go in, and the piece the crew's stair sequence means by "nosing"; no published guide walks through that install yet. A separate guide in this series covers [S4S and why a 1x8 measures what it measures](/learn/lumber-sizes-grades-and-milling/). Where hard-surface flooring butts into that flat-run nosing, the fit is never quite perfect, so a piece of [shoe](/glossary/moldings/#base-shoe) ripped to about 5/16 by 5/16 inch covers the seam. The arithmetic: flooring at 1/4 inch and nosing at 3/4 inch leaves the nosing standing [proud](/glossary/layout-and-shop-talk/#proud-shy) by 1/2 inch, and a 5/16 inch shoe leaves 3/16 inch of nosing showing, this shop's standard reveal; change the flooring thickness and the rip changes with it, the arithmetic being the check, not the 5/16 number alone. See [How to Install Baby Shoe at Stair Nosing](/learn/install-baby-shoe-stair-nosing/).

The model code sets four numbers here, worth quoting directly rather than paraphrasing, because the tolerance clauses matter as much as the headline figures. Riser height must not exceed 7-3/4 inches, and the tallest riser in a flight cannot exceed the shortest by more than 3/8 inch. Tread depth must not be less than 10 inches, with that same 3/8 inch limit between the deepest and shallowest tread in a flight. Nosing projection runs 3/4 to 1-1/4 inches, with a radius no greater than 9/16 inch or a bevel no greater than 1/2 inch, and it is not required at all where the tread itself runs 11 inches or deeper. [Headroom](/glossary/stairs/#headroom) through the stairway runs not less than 6 feet 8 inches, measured from the sloped line the nosings make.

A finished riser installs one of two ways, and the difference is what its outer end meets. A mitered riser belongs to an open staircase: its end meets the skirt board on the open stringer, and the two close in a mitered corner, one joint between two parts, never a return piece glued back onto the riser to hide its own end grain. A straight riser belongs to a staircase with walls on both sides: both ends go flat into the skirt boards, square cut, no [miter](/glossary/joints-and-cuts/#miter-joint). On this crew's jobs the skirt goes in before the riser, always, so a mitered riser's angle comes off the skirt board already on the wall, not a fixed number; a stair skirt follows the [rake](/glossary/stairs/#rake) of the stairs, so the angle changes staircase to staircase. See [How to Install a Mitered Stair Riser](/learn/install-mitered-stair-riser/) and [How to Install a Straight Stair Riser](/learn/install-straight-stair-riser/). The rough tread and riser the framer leaves are already there when this crew arrives; the finished riser is separate trim, cut and set after the skirt goes on.

 TreadRiserRiser height 7-3/4 inch max, measured nosing to nosingTread depth 10 inch min, nosing to nosingNosing overhang 3/4 to 1-1/4 inch, the short bar above the upper treadThe model code's four numbersRiser height: not more than 7-3/4 inches; the tallest and shortest riser in one flight within 3/8 inch of each other.Tread depth: not less than 10 inches; same 3/8 inch limit within a flight.Nosing: 3/4 to 1-1/4 inch projection, rounded to a radius of 9/16 inch or less, or beveled 1/2 inch or less; not required where the tread runs 11 inches or deeper.Headroom: not less than 6 feet 8 inches, measured up from the sloped line the nosings make (not drawn).

Section through two finished steps, not to scale. The numbers are the model code's limits, not house rules.

## Stringers: Cut vs Housed, and the Skirt Board

A [stringer](/glossary/stairs/#stringer-cut-housed) is the structural, angled member that carries the tread and riser, and it comes in two constructions. A cut, or open, stringer is notched to the tread and riser profile, the shape this crew's published stair guides describe wherever they describe a stringer. A housed, or closed, stringer has the tread and riser seat into [dadoes](/glossary/joints-and-cuts/#dado-groove) cut into a solid board instead of resting on notches. Every documented stringer in this crew's published guide library is a cut stringer; housed construction does not show up once, an absence in what has been published, not a rule that this crew never builds one.

A [skirt board](/glossary/stairs/#skirt-board-stairs) is a different part entirely, and it names one specific thing on this crew's jobs: the flat, closed trim board running the wall side of a staircase, no structural role at all, covering the joint where the stair framing meets the drywall. The published skirt guides call it typically 1x12, 11-1/4 inches actual. Material follows the finish: the drop-in guide calls MDF the most common choice in production work and says solid wood or primed finger-joint boards also work, the notched guide puts it as primed MDF or hardwood depending on the finish, and one field order for a stained stair called for alder skirts. One nominal-versus-actual example, from a major stair-parts manufacturer's own buyer's guide: its skirtboard stock ships as a 1x4, a 1x8, and a 1x12, each measuring 11/16 inch thick actual, thinner than a standard 1x board's 3/4 inch. That is a catalog fact, not a claim this crew buys from that catalog; this crew's own field records name a local supplier for skirt board stock instead.

Skirt boards install one of two ways. The drop-in method needs a gap the framer leaves between the stringer and the wall so the skirt can drop in from above; see [How to Install Stair Skirt Boards: Drop-In Method](/learn/install-skirt-boards/). Both methods cut the board to the stair's step profile; the difference is what the board goes behind. A drop-in skirt slides down into the framer's gap, its cut profile landing tight against the treads and risers. Notched skirt boards are the outside-skirt method, fitted over a tread and riser that are fully in place with no gap to slide into, and also the rescue when an inside wall was not prepped for a drop-in skirt and the board has to be cut over a tread and riser already there. See [How to Install Notched Skirt Boards](/learn/install-notched-skirt-boards/). Either way, the tread and riser in place when this crew arrives are the framer's rough ones, not the finished riser covered above.

Garage and patio step stringers are a different, exterior job with their own treated-lumber question; a separate guide in this series covers [step stringers on a slab](/learn/framing-and-treated-lumber-for-trim-carpenters/).

## Newel Posts: Box, Turned, Half, Pin-Top, Starting, and Landing

The [newel post](/glossary/stairs/#newel-post) is the anchor of a guarded rail system: every baluster and every guardrail section depends on the posts it lands between. A wall rail is the exception; it fastens to the wall, not to a post, so a closed staircase can run a full rail with no newel at all. [How to Install a Newel Post](/learn/install-newel-post/) sets the post with an L-bracket anchor kit, four brackets fastened to the bottom of the post and down into the floor framing or the stringer beneath a stair tread, never into tread material alone. Box newels are often hollow, with walls around 3/4 inch thick by that guide's number, so bracket screws get pre-drilled and kept away from the edges; a narrower box newel can have a solid base, so check which is on the post before you drill. If a 4 inch lag screw turns up on a stair job, it is a newel-setting fastener and nothing else; it is never the fastener for the rail-to-post connection covered under Balustrade Systems below.

Newel posts split into two builds. A box newel is a hollow, built-up post with a separate cap; a major stair-parts manufacturer sells removable-cap box newels with a choice of a flat or a pyramid cap on the same base, a real enough choice that one of this crew's own field texts asks specifically which style a job wants. That catalog's narrower box newels, 3-1/2 and 4-1/2 inches, have solid bases; its wider 6-1/4 and 7-1/2 inch newels ship hollow, built for an installation block. A turned newel is shaped on a lathe, and a major catalog sorts most of its turned newel series into two families, over-the-post pintop newels and post-to-post newels, though not every series offers both. A pin-top newel is the over-the-post kind, ending in a pin a fitting sits over instead of a flat block; that catalog's instructions put starting fittings at the base of the staircase specifically on pintop newels. A square-top newel is the post-to-post version, a squared block the rail lands on and butts into directly, usually with no fitting at the post. Do not confuse a square-top newel with a square-top baluster: the shared name points at the same system, since square-top balusters seat in the plowed rail that runs between post-to-post newels, but they are different parts, and this crew's own texts use "square top" a third way, for a box newel's flat cap as against a pyramid cap.

A half newel is a newel split down its length to sit flat against a wall, otherwise built the same as its full-post counterpart. Two more names describe where a newel sits rather than how it is built: a starting newel is the first post at the bottom of a staircase, and a landing, or intermediate, newel is set at a landing or a mid-run turn, a separate part, not one part under two names, as a major catalog's own full-staircase drawing labels them.

## Balustrade Systems: Post-to-Post vs Over-the-Post, and Why the Newel Type Comes First

A [balustrade](/glossary/stairs/#balustrade) is the umbrella word for the whole rail assembly: posts, the rail, and whatever infill stands between them. It comes in two systems, and a major stair-parts catalog's own design guide puts picking the newel type first for a reason: the newel decides which system gets built before a single piece of rail gets cut.

A [post-to-post](/glossary/stairs/#over-the-post-vs-post-to-post) balustrade uses rail sections that connect to the upper square block of the newel, a straight butt joint with no curved transition piece needed. An over-the-post balustrade lets the rail flow continuously over the newels and balusters instead of stopping at each post, needing a fitting and a rail bolt at every post. A post-to-post run usually skips the rail bolt at the newel itself, that joint being the glue, pins and trim screws of the house rule below, and saves the rail bolt for a splice or a fitting. This crew's own published metal-baluster guide covers post-to-post construction specifically, rail ends butting straight into the newel face.

Whichever system a job calls for, the newel connection follows one house standard: glue, tack with 18-gauge 1-3/4 inch pins to hold the rail while the real fasteners go in, then two 2-1/2 inch [trim screws](/glossary/materials/#trim-head-screw-pilot-hole) pre-drilled at an angle like a pocket screw. The screws do the real holding; the pins only tack. Never a 4 inch lag screw here, that is a newel-setting fastener, and never a 23-gauge pin, which is for delicate work like the baby shoe. A rail bolt joins one fitting to the next rail section on an over-the-post run, covered under Fittings below.

## Handrail: Plowed vs Unplowed, Shoe Rail and Fillet

A rail comes plowed or unplowed, and the difference decides which balusters it can take. Plowed means a groove, the plow, is run into the underside of the rail for square-top wood balusters to seat into. Unplowed, which a major stair-parts catalog also calls non-plowed, suits pin-top wood and iron balusters instead: the catalog's own language is that unplowed rail gives a seamless integration with metal and round balusters, while plowed rail is the flawless fit for square-top stock. That catalog sells plowed rail in two widths, 1-1/4 and 1-3/4 inches, and the plow has to match the baluster stock exactly: one of this crew's own field records describes a railing ordered for 1-3/4 inch balusters whose bottom rail arrived plowed for 1-1/2, stopping the stairs cold until the right rail showed up.

A shoe rail is the plowed bottom rail of a balustrade system, the piece the bottoms of square-top wood balusters seat into, and a fillet is the decorative strip set into the plow between those balusters, along both the shoe rail and the handrail above. The word collides with two other parts on this crew's jobs: a shoe rail is not a baluster shoe, the collar over a drilled hole on a metal baluster, and it is not base shoe, the baseboard-height molding [a separate guide in this series](/learn/trim-profiles-casing-base-and-molding-families/) covers. This crew's own field records confirm both as real, ordered parts, one asking for shoe run along the sides of a shoe rail and another for replacing fillet strips top and bottom on an existing run.

## Handrail Profile Numbers, and the Graspable-Rail Code (Type I and Type II)

Rail profiles get ordered by number, not by sample. A major stair-parts manufacturer's own history page credits itself with originating the 6010 handrail along with the 4040 and 4091 newels, and calls them products commonly used in stair parts today. This crew's own published metal-baluster guide describes its rail stock as "typically 6010, 6210, or a similar standard profile," and this crew's own yard has quoted material by that number directly, in two separate texts about 6010 bending rail, one of them for maple.

A handrail profile is sold in a range of cross sections and sizes, non-plowed, plowed, or as a bending rail for a curved run. Most non-plowed listings carry a construction code on the catalog page, FJ for finger joint, SC for solid cap, ENG for engineered, or SS for solid with no joints at all, though not every profile lists all four. A wall-mount rail is a separate, smaller profile, sold by the same catalog in two sizes, covered under Wall Rail below. On most fittings, the second digit of the part number matches the second digit of the rail's, the catalog's own rule for keeping a profile matched end to end; one series in the line puts a letter in that spot instead.

The plan behind this guide listed 6010, 6210, 6900 and 6519, plus a wall-rail number, and flagged the set for a digit check. 6010 and 6210 check out against a major stair-parts manufacturer's 88-page 2025 buyer's guide; 6900 and 6519 appear nowhere in it. Each stair-parts maker numbers its own profile line, so a 6900 or 6519 on a ticket is a different maker's number for a different shape, not this catalog's. This crew's own yard has quoted the 6010 number by text more than once.

The graspable-rail code sorts a passing rail into one of two types by shape, not by manufacturer, and it also accepts a shape that can be shown to grip just as well. A [Type I](/glossary/stairs/#code-terms-rail-height-graspability-4in-sphere-rule) rail has a circular cross section between 1-1/4 and 2 inches across, or, if not round, a perimeter of 4 to 6-1/4 inches with a cross section no more than 2-1/4 inches. A Type II rail runs a bigger perimeter than that and qualifies instead by carrying a graspable finger recess on both sides: the recess begins within 3/4 inch of the tallest point, runs at least 5/16 inch deep within 7/8 inch of the widest point, continues at least 3/8 inch farther down, reaching a level at least 1-3/4 inches below the top, and the width above the recess falls between 1-1/4 and 2-3/4 inches. Whether a specific stock profile meets Type I or Type II is a measurement question for the maker's own spec sheet, not something a catalog drawing settles; the maker sells its profiles as code-compliant handrails, and that claim is theirs to confirm.

One field fact matters more on a real job than either code type: square handrails fail inspection in Papillion and La Vista, and this crew's fix on those jobs is a rounded bread loaf profile, ordered from the yard by that name or swapped in for the square rail, or a finger groove cut into the sides of a square rail, a fix at least one inspector has accepted outright. That is this crew's experience in two specific cities, not a citation for what Omaha itself requires; the breadloaf rail gets its own full treatment in the last section of this guide.

## Fittings: Volute, Turnout, Easing, Gooseneck, Quarterturn, Rail Bolt, and Rosette

Fittings let a rail change direction or pitch without a joint landing at a post, and each has a real name worth using correctly. A [volute](/glossary/stairs/#volute-turnout) is the scroll-shaped fitting at a starting newel that sits over a pin-top post, sold in left-hand and right-hand versions plus a vertical volute variant. A turnout does a related but simpler job at the same spot, an outward curve rather than a full scroll; the two are not interchangeable, so read which a job calls for. A starting easing with cap starts a rail off a pin-top newel at the bottom of a run; an up easing and an overeasing change a rail's pitch partway through a run instead. A tandem cap, an opening cap, a coped end, and a returned end round out the other transition fittings a catalog sells for closing two rail sections cleanly.

A gooseneck fitting joins a rail running parallel with the stringer up to a higher rail on a landing or balcony, carrying a rake section into a level run; some styles ship with a cap for use over a pin-top newel, others do not. A level quarterturn takes a rail through a 90 degree turn in a flat run, and a quarterturn cap does that same turn with a newel cap built in, again over a pin-top post.

A rail fitting joins to a straight rail section with a [rail bolt](/glossary/stairs/#rail-bolt), a hidden, hanger-style bolt threaded into both pieces and drawn tight with a nut reached through an access hole underneath, which then gets plugged. This crew's own published guide for setting one fitting states that every joint in that job gets glued as well as bolted, even though the bolt does the structural work. See [How to Install a Handrail Fitting](/learn/install-handrail-fitting/).

A rosette, in the stair sense this section means, is a flat wood plate a rail lands against where a run dies into a wall instead of a post; a major stair-parts catalog lists six rosette models, all 3/4 inch thick. This is a different part from the rosette [a separate guide in this series](/learn/trim-profiles-casing-base-and-molding-families/) glosses as a casing corner block; both are flat blocks a piece of trim lands against, which is where the shared name comes from, but one sits at a casing corner and the other where a rail meets a wall. This crew's own field records confirm rosettes as a real, ordered part at wall terminations.

## Balusters: Wood and Iron Stock Sizes, Pin-Top vs Square-Top

A [baluster](/glossary/stairs/#baluster), also called a spindle or a picket, is the vertical piece that stands between the rail and the floor or tread below it. Wood balusters come pin-top or square-top: a pin-top has a rounded top that fits smoothly into an unplowed rail, a square-top is built for a plowed rail with fillet alongside it, and it can be a plain square stick top to bottom or a design that mixes turned and squared segments. Iron balusters come in a few stock sizes, 1/2 inch square being the common one in that catalog, with 9/16, 5/8 and 3/4 inch sizes also sold by its shoe pages, hollow or solid, in eight finishes. Pattern names in this crew's own published guide run to plain square, single twist, double twist, basket, and scroll; its field orders add straights and knuckles, a knuckle being a collar that slides onto a plain baluster. On a metal baluster, a [shoe](/glossary/stairs/#baluster-shoe), the collar covering the drilled hole at top and bottom, has to match the baluster's size and shape or it will not seat; the one catalog exception is a universal remodel shoe made to fit either a 1/2 or a 9/16 inch baluster.

Metal baluster work runs on house numbers, every one of them a rule, not a guideline. The rail hole gets drilled with a [spade bit](/glossary/tools/#spade-bit) to 1/2 inch, deep enough only to seat the baluster snugly; the floor hole gets drilled 3/4 inch, about 6 inches deep, so a baluster cut a little long or short still fits, and the shoe below covers the bigger hole anyway. On the rake, [three balusters go on every tread](/glossary/stairs/#spindle-count-code), about 3-3/8 inch center to center; a straight run opens slightly to about 3-1/2 inch center to center, deliberately tighter than code allows, so it does not read looser than the rake beside it. That house spacing sits well inside the 4-3/8 inch sphere the model code allows on the open side of a stair, and inside the 4 inch sphere it allows on a level guard. The code figure is the ceiling, never the target.

This work is two phases, not two steps, marking two separate trips with the painters in between. Phase 1 builds the rail, secures it to the newel posts, lays out the spacing, and drills every hole, unfinished at this stage on purpose; see [How to Build a Handrail for Metal Balusters Like a Pro](/learn/metal-balusters/). Phase 2, after the painters have finished the rail, cuts each baluster to length, sets it, and secures it with epoxy at the bottom and silicone at the top; see [How to Secure and Finish a Stair Baluster](/learn/secure-baluster-in-stair-railing/). It is two pay units because it is two trips, not a preference for double-checking the work. The epoxy is a two-part dispenser tube that mixes through its own nozzle as it is squeezed out, no batch to mix by hand, a product class a major stair-parts catalog sells with mixing nozzles, in tube sizes the maker rates at roughly 20 balusters for one and 50 to 70 for another; a whole set at once is about not wasting nozzles and keeping a finished home clean, not bond strength. Shoes go on before a baluster locks in place; the shoes this crew's guide describes cannot be added after.

Baluster timing against the flooring schedule starts with the flat-run nosing: laying the 1x8 before the newel posts go in takes this crew off the flooring schedule, because the flooring crew floors up to the nosing afterward, whatever they lay. On the stairs themselves a stair cap does the same job, but stair caps are an upgrade, not the standard. From there the house rule has three branches. With no stair caps and carpet coming, balusters go in before the carpet, so the bottoms can be set into the subfloor cleanly and the carpet crew cuts around them. With no wood nosing and a finished floor like LVP running under the rail, balusters go in after that flooring. And wherever a baluster lands in carpet, it always goes in before the carpet, with no exception; that is a sequencing rule for new work, and a remodel with carpet already down is a different question. Any combination outside those three is a call to make before committing, not a guess.

## False Tread, Return Nosing, Landing Tread, and the Bullnose Starting Step

A [false tread](/glossary/stairs/#false-tread) and a stair cap are the same part with two names, never two separate services. It is a finished piece applied at the end of a rough tread and riser, with the carpet running down the middle over the rough stair, to make the run read as solid wood treads with a carpet runner, without the cost of building full wood treads across every step. Set against a wall, it is the inside version; on the open side, where a guardrail also has to protect the edge, it is the outside version. This crew's own published guide for the part uses all three names in its introduction, a stair cap, an end cap, or a false tread, and treats them as one job. Like the finished riser above, it goes up unfinished; the painters finish it to match the rest of the run. See [How to Install a False Tread Stair End Cap](/learn/install-false-tread-stair-end-cap/).

A return nosing wraps the nosing profile around an open, unsupported end of a tread, where the tread edge would otherwise show raw. A major stair-parts catalog sells this as a lineal piece cut to length, alongside ready-made return nosings, including a coped, reversible version. A [landing tread](/glossary/stairs/#landing-landing-tread) is a related but different piece: the trim and flooring detail at the point where the top step meets the landing floor, sold by the same catalog as its own lineal stock in a range of widths. This crew's own answer to that same condition on a flat run is the 1x8 S4S nosing covered earlier in this guide, a house-specific solution to the same problem rather than a catalog piece.

A bullnose starting step is a factory-built first step at the base of a staircase, sized to work with either a pin-top newel and its starting fittings or a post-to-post newel with a box newel base, depending on the model, and sold in a reversible version that trims to length on site. A tread bracket, a thin decorative piece under an open tread end, may show up on the same order.

## Guard Height and Baluster Spacing: the Code Numbers, and the House Number Beside Them

The model code uses two different words for two different jobs, and this crew treats the distinction as absolute. A [guard](/glossary/stairs/#guard-guardrail), the code's own word, is the barrier that keeps someone from falling off an open-sided walking surface; on this crew's jobs it usually carries balusters or another infill, though a solid half wall does the same job with no infill at all. A wall-mount handrail is for gripping and never carries balusters; on an open stair, the rail people grip is usually also the top of the guard, and that rail does carry them. A stair rail system usually performs both jobs at once, since the same rail people grab is also the top of the guard on an open stair, and that overlap is exactly why the two words stay precise rather than becoming synonyms. This crew's rule keeps the two guide families apart: a baluster or guardrail guide is not to point at the wall-mount rail guides, and this guide follows that rule in its own sections.

Required guards, per the model code, cover any open-sided walking surface, floor, stair, ramp, or landing, more than 30 inches above the floor or grade within 36 inches horizontally of the open edge. Guard height runs not less than 36 inches above the walking surface or the line connecting the nosings, except a guard on the open side of a stair may be as low as 34 inches, and where the top of that guard also serves as the handrail, it runs 34 to 38. Openings cannot pass a 4 inch sphere, with two exceptions: the triangular opening at a stair's open side, formed by the riser, tread, and bottom rail, allows up to 6 inches, and the open side of a stair overall allows up to 4-3/8. Handrails, by contrast, are required on at least one side of any flight with four or more risers, at 34 to 38 inches measured from the sloped plane the nosings make, not the tread itself; a volute, turnout, or starting easing may exceed that height over the lowest tread, and a fitting or bending used for a transition between flights, at a winder, from handrail to guard, or at the start of a flight may exceed 38 inches at the fitting.

This shop sets a house number inside that code range rather than picking a point on it job to job. Every baluster guardrail on this crew's jobs is set at 36-1/4 inches to the top of the rail, measured from the walking surface, which lands inside the code range at every point: the wood nosing counts as that walking surface on a flat run, the tread nosing on the stairs. That number applies to a [horizontal bar railing](/glossary/stairs/#horizontal-bar-railing) exactly as it applies to a baluster railing, since the rail, posts, and height are one system across every infill, whether metal balusters, horizontal bars, cable, or glass; only what stands between the rails changes. A horizontal bar railing is a variant of the standard baluster railing built the same way, except the bars install with the posts as the run goes together rather than being drilled and set after the rail is up, secured with silicone rather than epoxy at each end, and counted by linear foot of rail rather than by baluster count. See [How to Install Horizontal Bar Railing](/learn/install-horizontal-bar-railing/).

## Wall Rail, Rail Brackets, and Wall Cap

A [wall rail](/glossary/stairs/#wall-rail-rail-bracket) is a handrail mounted directly to the wall rather than carried on balusters and posts, and this section is the one place in this guide's body where the wall-mount rail guides get linked, on purpose, since a baluster or guardrail section never should; the Related Guides list at the end rounds up every guide this vocabulary touches. Its brackets land on a stud, never a drywall anchor, a rule this crew's own interior wall-mount guides state without exception; one of them puts the sideways force of someone stumbling on the stairs at over 200 pounds on a single bracket. Typical spacing on a run is 32 to 48 inches on center, a figure this crew's own published guide states directly, landed on whichever stud falls closest along the [pitch line](/glossary/stairs/#pitch-pitch-line), the angled reference tracking the stair's own slope. A major stair-parts catalog sells brackets sized wall-to-center at 2-3/4, 2-7/8, 3-1/4, or 3-3/8 inches depending on the model; the model code separately requires not less than 1-1/2 inches of clear space between the wall and the rail.

A rail end [returns](/glossary/moldings/#return-self-return) to the wall rather than stopping open, unless it lands on a post; the return is glued and pinned the same way any mitered joint gets closed on this crew's jobs; see [How to Build a Wall-Mount Handrail](/learn/mount-handrail-wall/) for building it, and [How to Mount a Handrail to the Wall](/learn/mount-wall-handrail/) and [How to Install a Handrail Bracket](/learn/handrail-bracket-for-stair-rail/) for setting it. Height sits in the 34 to 38 inch code range covered above; one of this crew's own published guides adds that most carpenters set the height at 34 to 36, that guide's own working range, not a separate house number, since the 36-1/4 inch house standard set earlier applies to the baluster guardrail only, not a wall-mount rail. Billing follows the bracket, not the foot: attaching a wall rail is measured and charged by bracket count, separate from building the rail itself.

An exterior wall-mount rail on a garage or patio step follows this same wall-rail hardware, covered in [How to Install a Garage Step Handrail](/learn/install-garage-step-handrail/), with no steps content repeated here.

The stairs sense of "wall cap" is the one this library already defines: a wood cap that finishes the top of a knee wall or half wall along a stair, not a handrail and not gripped for support. See [wall cap](/glossary/stairs/#cap-rail-wall-cap) and [How to Install a Wood Wall Cap](/learn/install-wood-wall-cap/). A separate guide in this series covers [the other use of the same two words](/learn/wall-treatment-and-fireplace-trim-vocabulary/).

## Stair-Part Species, and the "Breadloaf Rail"

This crew's stair parts come from a defined list of species, drawn from a major stair-parts manufacturer's own species guide and from this crew's own material and field records; what each species looks like, weighs, or smells like is a separate guide's territory. The catalog stocks Red Oak, White Oak, Poplar, Hard Maple, Mahogany, and Primed as standard, with Hickory, Cherry, Walnut, Alder, Beech, White Pine, Southern Yellow Pine, Spruce Pine Fir, and Brazilian Cherry available special order. This crew's own published guides name oak or maple for wood nosing, a stained cherry or similar hardwood for a newel post caption, and poplar as the usual painted baby shoe; its field records show 1x8 as the flat-run nosing stock, most often maple or oak, an all-alder stair package on one job, and a local supplier as the preferred source for maple breadloaf rail specifically.

A [breadloaf rail](/glossary/stairs/#bread-loaf-finger-groove-rail-profiles) is not a product name in the catalog this guide leans on; the word describes a shape. It is this crew's shorthand, and its glossary's, for one of two fixes to a square handrail that fails a local graspability check: a rounded, bread-loaf-shaped profile, or a finger groove cut into the sides of a square profile instead. A major stair-parts manufacturer's 2025 buyer's guide never uses the word across its 88 pages, and this crew's own field records use it exactly the way that definition describes, asking the yard, in its own words, for "a 8ft maple breadloaf rail." The nearest catalog profiles by shape are the wall rails covered earlier, flat-bottomed, rounded sections rather than the taller molded shape of a 6010-type rail, the nearest match by cross section; neither is sold under the bread loaf name in that catalog.

## Stair Parts Quick Reference

Every part above, where it sits, the house or code number if one applies, and which guide covers it.

| Part | Where It Sits | House or Code Number | Guide |
| --- | --- | --- | --- |
| Tread | The board you step on | 10 inch min. depth (code) | - |
| Riser, finish sense | Between treads, interior | 7-3/4 inch max. height (code) | #1306, #1307 |
| Nosing, tread | Front overhang of a tread | 3/4 to 1-1/4 inch (code) | #1375 |
| Nosing, flat-run | 1x8 S4S base for the rail before newels | House rule | - |
| Baby shoe | Covers the gap at the flat-run nosing | 5/16 inch, 3/16 reveal (house) | #12538 |
| Skirt board | Wall-side finish trim over the framing | 1x12, 11-1/4 actual (the skirt guides) | #770, #1362 |
| Stringer | Structural board under tread and riser | - | - |
| Newel post | Anchor of the whole rail system | - | #778 |
| Starting newel | First post at the bottom of a run | - | #778 |
| Landing newel | Post at a landing or mid-run turn | - | #778 |
| Balustrade | Whole rail assembly, either system | - | #777 |
| Baluster guardrail | Top of the guard, carries balusters | 36-1/4 inch to top (house) | #777 |
| Wall rail | Handrail on the wall, no balusters | 34 to 38 inch (code) | #772, #773 |
| Shoe rail | Plowed bottom rail for balusters | - | - |
| Fillet | Strip set into the plow | - | - |
| Volute / turnout | Scroll or curve at a starting newel | - | #1348 |
| Gooseneck | Joins a rake rail to a landing rail | - | #1348 |
| Rail bolt | Hidden bolt, rail to fitting | - | #1348 |
| Rosette, stair sense | Wall-end plate a rail lands against | - | - |
| Baluster | Spindle between rail and floor | 1/2 top, 3/4 bottom hole (house) | #777, #1259 |
| Baluster shoe | Collar over a drilled hole | - | #1259 |
| False tread / stair cap | Finish over a rough or carpeted stair | - | #1363 |
| Return nosing | Wraps the nosing at an open tread end | - | - |
| Landing tread | Trim where a step meets the landing | - | - |
| Wall cap, stairs sense | Cap on a knee wall at a stair | - | #1376 |
| Guard | Barrier that carries balusters or infill | 36 inch, 34 on stair open side | - |
| Horizontal bar railing | Variant infill, bars not balusters | 36-1/4 inch, same as baluster | #7159 |
| Breadloaf rail | Rounded fix for failed graspability | - | - |

## Related Guides

- [How to Install Stair Skirt Boards: Drop-In Method](/learn/install-skirt-boards/)
- [How to Install a Newel Post](/learn/install-newel-post/)
- [How to Build a Handrail for Metal Balusters Like a Pro](/learn/metal-balusters/)
- [How to Secure and Finish a Stair Baluster](/learn/secure-baluster-in-stair-railing/)
- [How to Install a False Tread Stair End Cap](/learn/install-false-tread-stair-end-cap/)
- [How to Mount a Handrail to the Wall](/learn/mount-wall-handrail/)
- [Carpenter Hand Tools: What to Buy for Your Own Bag](/learn/carpenter-hand-tools/)

Written by **David Hospodka**, Sun’s Up Construction

David Hospodka learned finish carpentry from his father, alongside his brother Joel, and worked his way through college trimming houses. He then spent about ten years as a railroad bridge engineer, handling design, construction, maintenance and project management. He came back to finish carpentry full time in 2017.

[About Let’s Build Stuff](https://letsbuildstuff.co/about/)