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CURVED & HELICAL STAIRCASES, MADE TO COMMISSION
A DIVISION OF STAIRSPRO · @STAIRS_PRO_CANADA · TORONTO · BY APPOINTMENT

Twenty-two stairs, and no two alike

We have no catalogue, because we have never built the same stair twice. What follows is the record of what has been made — surveyed, engineered, and set down for the people who commission this kind of work.

Ø 3800 OPEN-WELL HELIX — 14 RISERS — 1.45 TURNS
Sculptural bronze curved staircase, the lead commission seen from the hall
THE COMMISSION
The same bronze staircase seen from the landing above
FROM THE LANDING
Detail of the bronze stringer as it turns through the well
STRINGER DETAIL
AS BUILT · COMMISSION 019
DEVIATION FROM MODEL: 1/16″
COMMISSIONS BUILT
22
Each one a single, unrepeated design. Roughly half are under NDA.
BUILD TOLERANCE
±1/16″
Measured against the model at handover on every commission.
LONGEST FREE SPAN
22 ft
Unsupported curved flight, rolled steel box stringer.
TYPICAL TIMELINE
9 – 12 weeks
First conversation to the day you walk on it.
ON THE WORK

Why a curved stair is a different trade from a straight one, and what that means for the way we work.

A curved stair is not a staircase with a bend in it. Every tread is a different shape, every baluster meets the rail at a different angle, and the handrail is one continuous line that has to feel right in the hand of somebody who is not looking at it. There is no standard part in the whole assembly, and there is nowhere to hide an error.

That is why the work begins with measurement rather than drawing. We scan the opening as it has actually been built — walls out of plumb, floors not quite level, the beam nobody told the architect about — and model the stair into the space that exists rather than the space on the plan. The geometry follows the house. Not the other way round.

Everything is then built and assembled to your live dimensions at our factory, taken apart, packaged and prepared for shipping. Our own crew installs across Canada, and beyond that we support your installer directly. A commission usually runs nine to twelve weeks from the confirmation of architectural drawings and renderings.

SHEET 01

Open Riser

ALSO CALLED: OPEN TREAD · FLOATING TREAD · SEE-THROUGH STAIR
Open riser curved staircase with clear gaps between every tread
01/A
The formRolled steel spine, solid treads, nothing between them.
Open riser staircase with open gaps between the treads and a glass balustrade
01/B
Solid walnut treads on a rolled steel spine. Seen from the top landing, the open risers stack into a continuous spiral with no structure visible anywhere in the well.
Warm open riser spiral staircase with planting and a suspended light
01/C
A straight flight in white oak, seen down through the well. The open risers and the frameless glass keep the sightline from the landing to the room below completely clear.

Nothing between the treads. You see straight through the flight to the floor below, and the stair reads as a series of separate planes rather than a solid object. It is the form that keeps a room feeling open, and the one that punishes any error in setting out, because every gap is on display.

The structure sits entirely in the stringer. On a curve that means a rolled steel spine carrying each tread from a single edge, with the provisions for fixing hidden inside the section. Nothing is bolted through the face of a tread.

Rise consistency matters more here than anywhere else. With an open riser the eye reads the gaps as a rhythm, so a sixteenth of an inch of drift over a flight is visible from across the room.

TYPICAL SPECIFICATION
StructureReinforced and engineered steel spine or box stringer, rolled to the outer radius, approved by a structural engineer
RiserOpen, 4″ – 7″ gap to code
TreadSolid hardwood, stone or laminated glass
Tread thickness2″ – 5″
BalustradeFrameless glass, forged metal or steel rod
Rise consistencyWithin 1/16″ across the flight
Timeline9 – 12 weeks
SHEET 02

Closed Riser

ALSO CALLED: SOLID RISER · BOXED STAIR · PLASTER MONOLITH
Finished closed riser curved staircase, solid face between every tread
02/A
The formA closed front face, plastered flush or clad to match the treads.
Closed riser curved staircase seen from the front, continuous outer face
02/B
The outer string was floated in lime plaster over nine days so no joint would fall in the eye line from the entrance hall.
Closed riser curved staircase in white plaster seen from above
02/C
A single continuous outer face from ground to first floor. The balustrade is set into the tread edge so nothing interrupts the sweep.

A solid face between every tread, and an outer string turned to one continuous surface. Done properly the whole flight reads as a single piece of material that happens to be walkable, with no joint, shadow gap or fixing anywhere on it.

The difficulty is the finish, not the frame. A closed riser hides the steel but shows every imperfection in the skin over it, so the plaster or stone has to be worked on site over days rather than delivered in panels. Every joint closes dry.

It is the quietest stair we build. With the risers closed there is no drumming underfoot and no line of sight through the flight, which is why it suits a formal hall better than an open one.

TYPICAL SPECIFICATION
StructureReinforced and engineered steel plate stringers, closed carriage, approved by a structural engineer
RiserClosed, clad to match the tread or the wall
Outer faceHand-applied lime plaster, stone or powder-coated steel
TreadStone, engineered hardwood or solid timber
BalustradePlaster upstand, frameless glass or forged metal
Visible fixingsNone on any surface within reach
Timeline8 – 11 weeks
SHEET 03

Marble Staircases

ALSO CALLED: STONE STAIR · LIMESTONE · QUARTZ TREAD
Marble tread curved staircase with a glass balustrade and pendant lighting
03/A
The formBook-matched slabs, cut so the veining runs on through the flight.
Marble curved staircase with a curved glass balustrade and glass chandelier
03/B
Honed marble treads with a curved low-iron glass balustrade. The chandelier arrived before the stair did and could not be shortened, so the well was sized around it.
Sculptural stone staircase rising from a patterned marble floor
03/C
The stair lands on an existing marble floor laid in the nineteen twenties. We scanned the pattern and set the bottom step out to it rather than cutting into it.
White marble helical staircase seen from above with a glass chandelier
03/D
Helical marble flightBook-matched marble treads turning through a full helix, seen from the landing above. The chandelier hangs on the centre line of the well.
Cantilevered marble staircase with a frameless glass balustrade and lit treads
03/E
Cantilevered stone treadsMarble treads cantilevered from a concealed steel spine, with a frameless glass balustrade and light set into the underside of each tread.
Cantilevered marble staircase treads seen from below against a slatted timber wall
03/F
The same flight, from belowNothing visible holds the treads. The steel is buried in the wall and the stone is bonded to it, so the flight reads as slabs floating off the face.
Dark stone staircase treads with a continuous light line set into each nosing
03/G
Dark stone with integrated lightA continuous light line set into the nosing of every tread. The channel is cut into the stone before the tread is fixed, so there is no visible fitting.

Stone changes the engineering before it changes the look. A marble tread at sixty millimetres weighs four times what timber does, so the stringer, the fixings and the floor build all have to be worked back from the slab rather than the other way round.

We buy the block, not the slab. On a curved flight the veining has to run continuously from the bottom step to the top, which means every tread is cut in sequence from one piece of stone. Book-matched, or it is not worth doing.

Limestone, marble and quartz all behave differently underfoot and in wear. We will tell you which one suits a front hall with a dog and three children, and which one belongs in a room nobody walks through.

TYPICAL SPECIFICATION
StructureReinforced and engineered steel carriage sized to the slab weight, approved by a structural engineer
Tread materialMarble, limestone, quartz or granite
Tread thickness3/4″ – 2 1/2″ honed or polished
VeiningBook-matched, cut in sequence from a single block
Edge detailPencil round, bullnose or mitred to a solid edge
BalustradeFrameless low-iron glass or forged bronze
Timeline10 – 12 weeks, stone lead time included
SHEET 04

Residential

ALSO CALLED: PRIVATE HOUSE · HOME STAIR · DOMESTIC
Curved residential staircase in a furnished open plan living space
04/A
The formBuilt for a private house, to the architect’s drawings.
Curved residential staircase in a styled interior with sculptural vases
04/B
A plaster curve turned to one continuous outer face. The client wanted the stair to disappear into the wall and the wall to disappear into the ceiling.
Residential curved staircase with timber treads seen from the landing
04/C
Timber treads on a rolled steel spine, seen from the landing. The inner radius tightens as the flight reaches the upper floor.

A stair in a house has to do more than look right in a photograph. It is used in the dark, in socks, carrying things, by people of every age in the family, and it has to be quiet enough that somebody coming down at midnight does not wake the house.

The setting out is the hard part. It has to land square to the door, keep its rhythm past a window, and clear a light fitting that is almost always fixed before we arrive. We cut the strings to the room as built, not the room as drawn.

Almost everything else is open. Open or closed riser, stone or timber, glass or forged metal — a private commission is where we have the most freedom and the least tolerance for a stair that only works on paper.

TYPICAL SPECIFICATION
SettingPrivate houses, penthouses and family homes
Survey3D laser scan of the opening as built
RiserOpen or closed, to suit the room
TreadStone, engineered hardwood or solid timber
InstallFull supply and installation across Canada
Timeline8 – 12 weeks, survey to handover
SHEET 05

Commercial

ALSO CALLED: LOBBY STAIR · ATRIUM · RETAIL FEATURE
Sculptural commercial feature staircase in a gallery interior
05/A
The formSpecified for public use and loaded accordingly.
Commercial atrium staircase with a forged metal balustrade over an open well
05/B
An open-well flight through three storeys of atrium, with a forged balustrade detailed to be read from the floor below as much as from the stair itself.
Commercial feature staircase with a frameless glass balustrade
05/C
A cast form with frameless glass, installed before the surrounding fit-out so the finishes could be run into the stair rather than butted against it.

A commercial stair carries an order of magnitude more traffic than a house does and is inspected against a harder standard. The loading, the fire rating, the slip resistance and the handrail continuity are all set before anybody discusses what it looks like.

It is also the work where the stair is doing a job for the building. In a lobby or a gallery it is the thing people photograph and the thing that tells them where to go. We take on the surrounding plasterwork, joinery and ceiling as one package so the junctions are ours rather than somebody else’s problem.

Programmes are longer and the co-ordination is heavier, but the engineering is the same discipline. Steel rolled to a radius, welded seamlessly, finished so nothing shows.

TYPICAL SPECIFICATION
SettingLobbies, galleries, retail, hospitality and offices
StructureReinforced and engineered steel, approved by a structural engineer
ComplianceHandrail continuity, slip resistance, fire rating
BalustradeLaminated or tempered laminated glass, forged metal
Timeline10 – 12 weeks, to suit the site programme
SHEET 06

Ironwork

ALSO CALLED: WROUGHT IRON · FORGED BALUSTRADE · ORNAMENTAL METALWORK
Grand entrance hall staircase with a hand forged wrought iron balustrade
06/A
The formDrawn at full size, then shaped by hand.
Hand forged wrought iron balustrade with scrollwork on a curved stone staircase
06/B
A continuous scroll run around the curve of a stone flight. The pattern was set out on the floor at full size and adjusted three times before any metal was cut.
Ornamental wrought iron panel with brass detail on a curved staircase
06/C
A repeating panel with applied brass rosettes, made to match the gates at the entrance so the two read as one design.

Everything else on this page is cut, rolled and welded. Ironwork is shaped by hand, one bar at a time, by somebody who has spent years doing it. No two pieces come out exactly the same, and that is the point of it.

We can design a pattern for you from scratch, or you can send us a photograph or a drawing of something you like and we will recreate it, adjusted to fit your staircase and to meet code. We draw the pattern against your elevation at full size before any metal is cut, because a design that looks right on paper is often wrong once it is standing at 36″ beside a stone tread.

The same shop makes gates, railings, screens and window grilles, so the ironwork at your entrance and the ironwork on your staircase can be made to match.

Ironwork is powder coated in one of our 34 colours, or painted on site after installation in any Benjamin Moore colour. Gold, brass and copper details are hand painted on site by an artist.

TYPICAL SPECIFICATION
MethodShaped by hand from solid bar, not cast
Bar stock1/2″ – 1″ solid, sized to the span and the pattern
PatternYour design or ours, drawn full size before work starts
JointsWelded or collared — no visible fixings
FinishPowder coat in 34 colours, or painted on site in any Benjamin Moore colour
Metallic detailsGold, brass and copper hand painted on site by an artist
Timeline8 – 12 weeks, depending on the pattern

Materials

We hold a sample library and send sets out to studios before anything is specified. Nothing here is ordered from a catalogue photograph — stone in particular has to be seen in the room it is going into.

TREAD

Stone

Sintered stone, marble, granite or quartz. Honed or polished, book-matched across a flight where the slab allows it, and set on a steel substrate.

TREAD

Timber

Any species you want — white oak, red oak, walnut, maple, ash and beyond. Solid stock, milled in our own shop, stained or left natural.

STRUCTURE

Reinforced engineered steel

Laser-cut box or plate stringer, reinforced and engineered to the load, then rolled to radius. No visible welding or assembly marks.

FINISH

Powder coat or paint

Powder coated in one of 34 standard colours, or painted on site to any Benjamin Moore colour you choose.

BALUSTRADE

Glass, iron or steel

Tempered or laminated glass, available in a range of colours. Or custom wrought iron. Or laser-cut steel panels.

HANDRAIL

Stainless or timber

Stainless steel or solid wood. Bar, square or round profiles, sized to the hand.

LIGHTING

Integrated LED

A range of LED profiles recessed into the nosing or under the stringer. Choose your shade of light. Dimmable, and wired to a switch or to your smart home system.

Our order process

01

Conversation

We meet on site, talk it through over Zoom, or sit down with you at our boutique staircase showroom, where we go over your design expectations and select your upgrades.

WEEK 0
02

Survey

We laser-scan the live dimensions of each opening to create accurate architectural drawings.

WEEK 1
03

Design

Within two weeks we present a set of realistic 3D renderings alongside the architectural drawings.

WEEK 1 – 3
04

Fabrication

Built and assembled to your live dimensions at our factory, then taken apart, packaged and prepared for shipping.

WEEK 3 – 8
05

Installation

We offer installation across Canada by our own crew, from first bearing to final handrail.

WEEK 8 – 9
06

Installation support

For projects outside our installation service area we offer guidance over video call, or we can arrange for our specialists to meet you on site to facilitate the installation management.

WEEK 8 – 9

The stair was the only thing in the house we refused to compromise on.

CLIENT · PRIVATE RESIDENCE · 2024

What It Costs

We publish ranges rather than a single figure because each project’s price depends on the quantity, the reinforcement and supports required, the dimensions and the material upgrades.

$260k – $440k Covers most one and two storey residential and smaller commercial projects.

$440k – $1.7m Covers most high-end residential and most commercial projects.

$1.7m – $2.6m Covers most commercial, public or industrial staircase projects.

Below about $260,000, we suggest our geometrical staircase designs, which are more budget friendly and available at STAIRS PRO.

Visit the STAIRS PRO main site

The Atelier catalogue

The commissioned work in one document — the six ways we build, the materials, the order process and the cost ranges. Take it to your architect or designer.

PDF · 11 PAGES · 6 MB · We will not share your address.

Send us your drawings or design package, or book a meeting.

Send us your drawings or your design package and we will review them. Or book to meet on site, over Zoom, or at our boutique showroom, and we will go over your design requirements together.

A drawing review costs nothing and takes about a week. If you are a homeowner without drawings yet, that is fine — a photograph of the opening and a rough floor-to-floor height is enough for us to start.

  • Plan and section, any format, sketches accepted
  • Floor-to-floor dimension, if you have it
  • Opening size, or a photograph of the void
  • Timeline, and whether the slab is poured

Drawings are held in confidence and never published. We work under NDA on request, and we do not run a mailing list.