A steel newel post is the main post in a stair railing: it sits at the bottom of the stair, at landings and turns, and at the top, and it anchors the guard and handrail where they start, change direction or end. Because the railing pulls hardest on these posts, a steel newel needs a stronger section and better anchorage than the posts in between, and on a stair that needs a guard it must be designed for the guard loads in the Ontario Building Code. This guide covers where newel and railing posts go, how they attach to concrete, steel and wood stairs, and the cap and finish details that make them last.
Newel posts, railing posts and balusters
Stair railings use three kinds of vertical members, and it helps to name them the same way your fabricator does:
- Newel posts: the anchor posts at the start and end of each run and at every change of direction. Rails and handrails die into or onto them.
- Intermediate (line) posts: posts spaced along a straight run between newels to carry the top rail. Their spacing comes from the guard design.
- Balusters or pickets: the infill between posts. They keep people and objects from passing through the guard but carry little of the main load.
On a short residential stair, a single newel at the bottom and a wall or post at the top may be all the posts needed. A long flight with an open side, a landing and a return at the top can need several newels plus line posts. For an overview of picket, panel and glass styles, see steel stair railings and handrails.
Code points that affect a steel newel
The 2024 Ontario Building Code doesn't regulate newel posts by name, but the rules for guards and handrails decide what the newel has to do.
- Guard height. On a stair, guard height is measured vertically from a line drawn through the tread nosings. Guards are generally at least 1,070 mm high; guards within a dwelling unit can be 900 mm, as can exterior guards serving a single dwelling unit where the walking surface is no more than 1,800 mm above finished ground. The newel top has to work with those heights at both the stair and the landing.
- Handrail height. Required handrails are 865 mm to 1,070 mm high, measured from the nosing line or the landing surface. Where a separate handrail runs alongside the guard, it often attaches to the newel or line posts with brackets.
- Starting the handrail at a newel. For stairs serving a single dwelling unit or a house with a secondary suite, the code permits a handrail to start from a newel post or volute installed on the bottom tread, rather than at the bottom riser.
- Loads. Handrails and their supports must resist a concentrated load of at least 0.9 kN applied at any point and in any direction, and guards have their own load requirements in the code. A newel often carries both.
- Openings. Gaps beside the newel, including between the post and the first picket and under the bottom rail, still have to stop a 100 mm sphere.
Our guide to Ontario guard and handrail rules for steel railings covers the full set, including openings, climbability and the guard load table.
One point catches people out: Ontario's Supplementary Standard SB-7 gives deemed-to-comply guard details, but its scope is wood guards. A steel newel and railing is normally justified by design, so ask whether your project needs an engineer to sign off on the post, weld and anchorage.
Choosing the post section
Steel newel and railing posts are usually one of these:
| Section | Notes |
|---|---|
| Square HSS (tube) | The most common choice. Clean look, easy to cap, good strength in both directions. |
| Rectangular HSS | Used where the post must be deeper in the direction of the load, or to suit the stringer face. |
| Solid square or flat bar | Slim look for interior stairs. Strength depends on size and the base weld. |
| Round pipe or tube | Suits traditional and industrial railings, and pairs well with round handrails. |
| Built-up or decorative posts | Plate boxes, twisted bar or posts with cladding, for feature stairs. |
Size isn't a style decision on its own. The post section, its spacing, the base plate, the weld and the anchors are designed together to carry the guard load at the top rail. A thin post can look fine and still bend at the base when someone leans on the guard at the top of a stair. The steel railing dimensions guide explains how post spacing and anchorage interact.
How steel newel posts are anchored
Most railing failures start at the base of a post, so the anchorage deserves as much attention as the post itself.
On concrete stairs and slabs
- Surface mount with a base plate. The post is welded to a plate that is anchored to the concrete. Plate size, thickness and anchor type, embedment and edge distance are all part of the design. Anchors close to the edge of a step can break out the concrete.
- Core-drilled and grouted. A hole is cored into the concrete and the post is set in non-shrink grout or anchoring cement. This hides the fixing, but the concrete around the hole has to be thick and sound enough, and water must not sit in the pocket.
- Side (fascia) mount. Brackets fix the post to the face of the stair or slab edge, which keeps the treads clear and moves the anchors away from the top edge.
For the general trade-offs, see embedding steel posts in concrete vs base plates.
On steel stairs
On a steel stair, the newel is usually welded to the stringer or bolted to a plate welded to it. This is the strongest and cleanest detail, because the post and stair become one piece and the load goes straight into the stringer. Plan the post locations when the stair is detailed so the stringer can take them, and so posts don't land on a splice or connection.
On wood stairs and floors
A steel newel replacing a wood one on an existing stair is a common renovation. The post needs something solid to bolt to:
- Through-bolted to the stringer or to a rim joist with a tall steel plate that spreads the load.
- Bolted down through the floor to blocking added between the joists. A base plate screwed only into subfloor or a tread won't resist the guard load.
Whatever the stair, decide the anchorage before ordering, because it changes the length of the post and the plates welded to it.
Caps, finishes and details that last
Caps
Hollow steel posts should be capped. Options include:
- Flat welded cap plate, ground smooth, the cleanest modern look
- Bevelled or pyramid cap, which sheds water and suits exterior posts
- Ball, finial or decorative caps for traditional railings
- Handrail on top, where a continuous rail runs across the post tops and closes them
Outdoors, a sealed cap matters more than looks. Water that gets into a tube rusts it from the inside and can freeze and split it. If the post will be hot-dip galvanized, it needs vent and drain holes during galvanizing, which are then sealed or detailed so water can't collect.
Finishes
- Interior: primer and paint or powder coat.
- Exterior: hot-dip galvanizing, usually with paint or powder coat over it, especially near salted walkways and driveways.
- Touch-up: any field cutting or welding needs to be touched up to the same standard, or rust starts there first.
For how coatings hold up, see do steel railings rust.
Ordering steel newel and railing posts
To have posts made to fit, send your fabricator:
- A sketch or drawing of the stair in plan and elevation, showing where each post goes
- Floor-to-floor height and the tread and riser dimensions, measured to finished surfaces
- What each post mounts to (concrete, steel stringer, wood framing) and the mount type
- Guard and handrail heights you need, and whether the handrail runs on the posts or on the wall
- Post style and cap, and the infill you plan to use
- Finish: primed, painted or galvanized
We fabricate custom steel railings, newel posts and line posts in our CWB certified shop in Erin, with shop drawings prepared in-house, and we can prime or galvanize to suit. We fabricate and deliver across the GTA and Ontario; installation is by your installer or contractor.
Request a quote with your measurements or drawings, or see our services for miscellaneous steel fabrication.
Frequently asked questions
What is a steel newel post?
It is the main structural post of a stair railing, usually at the bottom of the stair, at landings and turns, and at the top. The guard rails and handrail start, change direction or end at the newel, so it carries more load than the intermediate posts and needs the strongest anchorage.
How do you anchor a steel newel post?
On concrete, with a base plate and anchors or by setting the post in a cored hole with grout. On a steel stair, by welding or bolting it to the stringer. On a wood stair, by bolting through the stringer or to blocked floor framing. The anchorage is sized by design for the guard and handrail loads.
How high should a newel post be?
High enough for the guard it supports. Under the 2024 Ontario Building Code, guards are generally at least 1,070 mm high, or 900 mm within a dwelling unit, measured on a stair from a line through the tread nosings. The post top is set to suit the guard and handrail heights.
Do steel newel posts need caps?
Hollow posts should be capped. A welded cap plate keeps water and debris out of the tube, which matters outdoors where water inside a post rusts it from within and can freeze. Caps can be flat, bevelled, pyramid or decorative.
