Spiral Stairs
Custom spiral staircase, built in our own factoryMetal · Wooden · Outdoor · Modular aluminum
A compact spiral staircase around one center column — for a loft, a library, a deck corner or a rooftop deck, where a straight run will not fit.
Double Building (DBM) is a spiral staircase manufacturer in Foshan, Guangdong. Send the floor-to-floor rise and the clear circle you can give the stair. We return shop drawings, build the helix in steel, wood or modular aluminum, trial-assemble it, and crate it in labelled stack order. Your local contractor installs.
Shop drawings · factory quote
Send rise, diameter and ship-to. We reply with shop drawings and a factory quote.
A spiral staircase that has already been stood up once
We stand every helix on the workshop floor, check the tread arc and headroom, then pack the column and treads in stack order.
Diameter drawn first
Send a sketch, a photo or the opening size. Shop drawings come back with diameter, rise and the top landing.
Steel, wood or aluminum
A metal spiral staircase, a wooden spiral staircase on a steel column, or a full modular aluminum helix.
Trial assembly
We stand the helix on the workshop floor and pack it in stack order before the crate leaves.
Labelled crate
Column, treads, sleeves and top rail leave labelled for ocean freight, with an assembly manual.
Metal, wooden, or outdoor and aluminum
One center column, three looks. Each is drawn to your opening, not picked from a size chart.
Metal Spiral Staircase
A steel spiral staircase: powder-coated column and steel-plate treads — a modern spiral staircase for lofts and split-level units.
Wooden Spiral Staircase
Solid hardwood treads and a hardwood top rail on a steel column, for villa libraries and country homes.
Outdoor & Aluminum Spiral Staircase
An outdoor spiral staircase in galvanized or stainless steel, or an aluminum spiral staircase built from modular aluminum stairs with a powder coat, for a deck corner or rooftop deck.
Spiral staircase range
Modular stairs, built to one approved drawing
If you searched for modular aluminum stairs, modular aluminium stairs or modular stairs, here they mean a full aluminum helix built as factory modules to one approved drawing — an aluminium spiral staircase, in British spelling. It is a material option on this spiral range, cut, finished and trial-assembled in Foshan — not a stock retail product.
Repeat units use the same idea in steel or hardwood: one drawing, identical modules, the same diameter and tread count from unit to unit.
From a tiny-home loft to a rooftop deck
Villa & Country Home
A library mezzanine or a loft stair that does not eat the room. A wooden spiral staircase pairs a steel column with hardwood treads; for a luxury spiral staircase, add a hardwood collar and wrought-iron infill.
New Home Build
House drawings often keep a tight circle for a study loft, loft access or a small second floor. We draw the helix to that circle; sections often pass through an ordinary interior door.
Apartment, Loft & Tiny Home
A small spiral staircase reaches the upper level without giving up a hallway. We draw the tread arc against the upper opening so headroom clears.
Deck & Rooftop
Spiral deck stairs, off a terrace or up to a rooftop deck, take a galvanized or stainless helix, or modular aluminum, with steel or composite treads.
Treads, column and infill
Four steps, every spiral
Drawn for approval
Column length, tread arc, top landing and the code-family list.
Fabrication
Column, treads and sleeves cut, welded and finished in our Foshan workshop.
Trial assembly
The helix stood on our workshop floor, checked, then taken down.
Stack-order crate
Column boxed apart from the treads, treads stacked stair-up; your local contractor installs.
Spiral stairs on our workshop floor
Shorts from the Double Building channel. Tap a clip to play it here.
Before you order a spiral
What rise and diameter can you build?
We do not work from a size chart. Column length and tread count follow your floor-to-floor rise, and the diameter follows the clear circle you send — from a compact spiral staircase for a loft to a wider helix for a main hall. Your local engineer checks the final numbers.
What sets the price?
Diameter, rise, material, tread and infill choice, finish, and the ship-to port. Every quote follows the shop drawings you approve; we do not publish a price list.
Metal, wooden, outdoor steel or modular aluminum — how do they differ?
Wooden: steel column with hardwood treads and top rail. Metal: steel column with steel-plate or chequer treads. Outdoor steel: galvanized or stainless helix. Modular aluminum: aluminum modules to one approved drawing, often outdoors.
Can a spiral go off a deck or up to a rooftop deck?
Yes. Outdoors we use a galvanized or stainless helix, or modular aluminum with a weather powder coat. Send the deck level and the clear circle at the bottom.
Can a licensed engineer in my country stamp the drawings?
Yes — a licensed engineer in your country stamps them; we do not. Shop drawings list IRC, IBC, AS 1657, AS 1288, NCC and CSA.
Do you install in the US?
No. We manufacture and export. The helix is crated photo-documented in stack order with an assembly manual, and your local contractor installs.
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