Introduction: Floating Circular Concrete Staircase

Picture of Floating Circular Concrete Staircase

This unique circular staircase at my casa in Mexico has no center support. It's 24 steps allow a 12' rise in a 10' diameter circular stairwell. I designed an built it with help from my son.
Circular stairs usually need a center support, but I wanted to have the center open, so I designed this one to cantilever from the wall, leaving a 3' open center.
To accurately form the wall and steps, I cut a dozen 5' -1/6's from 3/4" 
Rotating same boards around the pipe gave us the riser forms to pour the actual steps onto the ramp.

Step 1: Sketchup Plan

Picture of Sketchup Plan

Drawing it in sketch up made it possible to calculate step rise and run, rebar placement, and step placement.

Step 2:

Picture of

The circular wall that holds up the stairs is made from 5" foam blocks that leave a 3"  vertical and horizontal void for concrete and rebar. These styrofoam block forms are made in Mexico. I also used them for most of the walls in the house.
Bars to hold the steps had to be placed  in this wall as it was built, so I needed to know exactly where to place them so each step would have a rebar in tension off the wall. By drawing this staircase in 3/d (sketchup) , I could place the bars exactly.  The ramp/steps
We poured the ramp and steps 6 months after the wall was built.

Step 3: Landing and Circular Support Beam

Picture of Landing and Circular Support Beam

Because the steps ran 360 degrees, the landing had to support both the staircase and the upstairs floor. We formed a circular 1/2beam on the floor and lifted it up to pour the complete circular beam.
Half the beam was in the wall, and the half you see supports the floor.

Step 4: Forming the Spiral Ramp

Picture of Forming the Spiral Ramp

To accurately form the wall and stairs, I used a 20' 2" steel electric conduit pipe as a temporary center post.
I used a 2" u bolt fastened through the end of 6" wide plywood board to make sure the wall was round. 

The same boards stacked and rotated to form the bottom support for a foam/fiberglass form we made by tweaking 1" beadboard to the needed warped shape, then fiberglassing it.  We made two sections,glassed both sides with epoxy resin.


Step 5: Pouring Ramp

Picture of Pouring Ramp

Rebar gets added to the bars coming out of the wall, and an inside form of 1/4" plywood added to the inside.

The ramp was poured in 3 sections, glued at the joints with latex concrete adhesive. This let us reuse the fiberglass and support forms, just by rotating the plywood boards and locking in place.
The concrete was very high strength, mixed on site using super plasticizer to reduce water content.
All the concrete was consolidated with a spud vibrator.
The ramp is 3 inches thick.
You can see the "U" bars sticking out. They give a physical lock to the steps poured next.

Step 6: Rule # 1 Celebrate Victories

Picture of Rule # 1    Celebrate Victories

On a big long project like this it is important to break it down into smaller parts, just like an instructable.  You can then enjoy the successes that keep you going.
With only myself and my son Adam working on this part time, it took many weeks to complete, with many celebrations along the way. 

Step 7: Steps

Picture of Steps

The ramp support forms get rotated to the top of the ramp and become riser forms.
Because the forms stack on each other at the main tube, all I had to do was level them and set them at my marks on the wall that came from the sketchup drawing a year earlier.

Step 8: Finish

Picture of Finish

A  plaster finish on the wall and you have one solid staircase, with less than 1/8" deviation between step rise and run.
Someday we might cap the steps with tile or wood, but they look very sculptural as is.

Comments

EmilK2 (author)2015-07-20

Hi, I have a spiral staircase, an iron structure, but with problems on wall supports, and upside-down step frames...

It goes on for three floors (51 steps), with 100cm radius (3 ft. or so), with a central iron pole of 10-12cm (4-5").

Can I use this construction as a formwork to build it using concrete?

I think that by using vertical pieces to 'close' the step and a frame underneath plus some rods and wall supporting nails I may pour the liquid concrete in that frame...

What do you think?

Thanks a lot.

Emil from Greece (Crete island)

P.S. By the way, great job with that floating staircase!

boaslad (author)2013-08-22

Very beautiful. I have built something similar out of wood once (I'll NEVER do it again...). I would have never thought to use concrete, though. Wow.. just... wow.

Breygon (author)2013-08-22

THAT IS AWSOME! I have doodled designs for a house I would build if I won the lotto and it calls for a staircase something like this (though didn't envisage something as cool as this) in my design the centre area is not open to the stairs because I'd like a camera obscurer as the centre piece. great skills.

redfoxtrystman (author)2013-08-21

I have seen many ables on this site but not one that can stand up to this and the work you (and your helpers if any) did. Amazing work. I even had to share this on other sites.

poofrabbit (author)2013-08-21

Oh wow I adore this, I wish I had a more technical mindset to pull something like this off. I'm in awe of people who do. Nice work and amazing craftsmanship!

spyder2021 (author)2013-08-21

love how fluid and smooth it looks. great job

kenbob (author)2013-08-21

You are an artist, well a craftsman and an artist. This is a thing of beauty. I have designed and built curved staircases, but never envisioned this. I love it. Great instructable!!

chuckyd (author)2013-08-25

Can you let us know in a year if it's still standing, and if any cracks have developed?

jerryjaksha (author)chuckyd2017-07-02

over 5 years old and solid as reinforced concrete- no cracks

jerryjaksha (author)chuckyd2013-08-29

It has been up over a year and has no cracks- way too much steel. When in doubt- add steel to your concrete. There is no give at all, like you would get in a wood stair.

sachin 18 (author)2016-02-08

I want make this type of stairs pleas help me...

jerryjaksha (author)sachin 182017-07-02

Looks like you will need an expensive steel spiral support beam. Steps would need to be welded on.

robtheraccoon (author)2015-04-04

so beautiful I want this in my dream home. does it have to be holding onto a wall or is it strong enough to hold it self up?

Since It has no center post I believe it needs the wall for support.

It is possible that it has enough steel to act like a spring hanging from the circular beam, and supported by the floor, but I wouldn't bet on it.
I didn't design it to stand without the wall.

Any engineers out there who could do a computer analysis? Might make a good finite analysis project for a grad school engineer.

colinmcc (author)2013-08-25

Good work! I build ICF structures in BC, Canada, (using ICFs from Quadlock) Tell us more about those Mexican ICFs you used please.

jerryjaksha (author)colinmcc2013-10-17

The icf blocks in Mexico are 3' x 5" wide x"8" high. They leave a 3" concrete rod vertical and horizontal centered every 8". Not too much insulation, but it is Mexico.
We cut vertical slots with a soldering gun so we could bend blocks at the stairwell.
We used lots of packing tape to keep things in line.

shortkow (author)2013-09-28

A rather incredible set of stairs you have made there, but i see one flaw, no fireman's pole down the center!

jerryjaksha (author)shortkow2013-10-17

A fire pole would be fun. I have another spot for that- at my fire pole/elevator that will take me 12' down to the water. -- one of my next instructables...

pkien (author)2013-08-25

Truly great craftsmanship. But "winders" as these wedge-shaped stairs are called, have been found to be perilous to traverse, especially for young, old, obese, pregnant, anyone with an infirmity, on anyone new to these winding stairs with their irregularly sized tread spaces. As well, without railings, any misstep would mean a fall, possibly a long one. Residences, in many jurisdictions, are not subject to the strict codes that public buildings are, but nevertheless, precautions would be advisable. The discipline of "universal design" aims to make the built environment readily accessible to all.

badvaquero (author)pkien2013-09-20

the realing to the out side of the circle it will not interfear whit the beuty of your work as you will leave the floting image to your stair, and it will be more usable as the steps are wider and people will pefer to walk in that part. i tink that, its your space, its youre art work, people should learn and see were there are going, as treknology wrote,its not a public stair that should fit every one, it should fit you and yours. congratulains to the work and to the wining of the contest. sorry my inglish writing its not that good.

jerryjaksha (author)pkien2013-08-29

I agree, stairs are dangerous for the above mentioned young , old, etc.. That is why I left a 4'x4' closet with temporary roof for the home built elevator I will hopefully build before I need it. The elevator will of course not meet codes or be nearly as safe as as walking over the threshold of a single story house.

Treknology (author)pkien2013-08-26

My father built a helical stair-case off the front balcony which descends the full level through a mere 180 degrees. The spacing of the steps is too small and tight meaning that for anyone the railing is a necessity.

Putting a railing on this work of art would be desecration. Apart from those who are genuinely frail and infirm, people should learn to look where they are going.

badvaquero (author)2013-09-20

woww, exelente trabajo. muchas felicidades. obsolutly great work, nicely done and the finish is as we say in mexico "conmadres". congratulations.

jeno (author)2013-09-15

What an absolutely stunning piece of work!
Shapes like this appear in my dreams but I don't know if I'd be brave enough to try to make them reality.

bigbootyzulu (author)2013-09-10

Truly awesome and inspiring, I'm a big fan

origami99 (author)2013-09-05

Spectacular!

PaulaTx1 (author)2013-09-05

That staircase is the most beautiful staircase I have ever seen. You are a master craftsman. Thank you for posting the pictures and the instructable. Your staircase is a work of art!

glennmaggard (author)2013-09-04

Congrats on your Grand Prize winning entry! That's a pretty spectacular project, and thanks for sharing the techniques used.

jerryjaksha (author)2013-09-04

Grand Prize- Wow!
Thank you everyone for your positive feedback. It has been great to share the construction of my stairs with all of you. It was a real challenge to come up with a forming method that we could make with the tools at hand. Once I figured the forming out, it was just a bunch of hard work.

poofrabbit (author)2013-08-31

Just wanted to say congratulations on being a finalists in the Concrete & Casting Contest! This was a fantastic idea and a lovely instructable! Good luck!

Arghus (author)2013-08-30

stunning piece of art, nice work

espdp2 (author)2013-08-30

Beautiful! I'm adding this to my collection on home building ideas, even if I might not be allowed to use it someday. Is there any chance that you could release the finished Sketchup files that you produced? Thank you for making beauty.

pkien (author)2013-08-26

I can't see that giving this work "style points" for aesthetics would outweigh it's flawed functioning. Architecture has had three main principles since the times of ancient Greek civilization, all of which are requirements: firmness, commodity, and delight. The staircase fails the test of usability, also known as commodity, or fitness for its purpose. Yes, it delights the eye, and is structurally sound; but with the danger inherent in it's design, it is not usable except for certain classes of people, and then only under certain conditions. The notion of perfection that the aesthetics invoke does not recognize the actual human condition, which is flawed and imperfect.

onemoroni1 (author)2013-08-25

This is very well done. However I would like to see a handrail.

jerryjaksha (author)onemoroni12013-08-26

The handrail is on the way. It will be a 24' long bent laminated wood one attached to the wall. You walk next to the wall on the 16" wide area there so that is where the rail needs to be for a hand hold. I am still considering a potential rail on the inside, but I hate to mess with the sculptural look.
There is an alternate stairs to our bedroom through the outside deck which we use when fuzzy headed.

onemoroni1 (author)jerryjaksha2013-08-26

Sounds beautiful. I agree, your project extends beyond function to a work of art. I should have assumed there would be a hand rail.

ellisgl (author)onemoroni12013-08-25

I was thinking the same thing. Nothing says fun like a couple drinks and trip down the stairs.

smelo (author)2013-08-26

interesting ... very interesting, a work of art!

jtmcdole (author)2013-08-25

I love seeing someone else using Sketchup to plan their builds! I did just the same when building a spiral staircase in my buddies house - though yours is much nicer. Well done!

Carlos Marmo (author)2013-08-25

Lovely concrete!

http://blog-imgs-44-origin.fc2.com/m/e/t/metamorphoseislands/Museu-nacional-brasilia.jpeg

gourdhedd (author)2013-08-25

Remarkable work. I've seen quite a few stair forms, but never any as simple and functional as these are. Must be "Yankee ingenuity" meets "South of the Border style".

Hebert (author)2013-08-25

Nice work, congratulations.

tseay (author)2013-08-25

Wow awesome project. I am a little considered though. The top of all the steps are going to be in tension and as you know concrete is great in compression, but will break off and break in tension. I would like to see where you placed the rebar relative to the top surface of the step. Do you have any detail drawings with dimensions?
Keep a watch on any concrete breaking or cracking. Thanks for showing the photos and details. What did you use to meld the concrete layers together?
I think it looks beautiful and don't cover with wood or tile. But consider a concrete finish of acid wash. It leaves such a beautiful finish, marble look or a rusty water color. Really amazing look. Hope it last for generations. :)

canida (author)2013-08-25

This is beautiful!

nodttiurp (author)2013-08-25

A work of art! It would be illegal in the USA under most building codes. For a model of the codes see http://www.salterspiralstair.com/technical/building-code/

steampsycho (author)2013-08-25

I will be making note of this for the sweet day when I can build my own place. This is simply fantastic. Nearly what I had envisioned for my future place.

destrip (author)2013-08-25

Very good job. But tell me, are not you going to install a stairway fence ? I think it's very dangerous since you can fall and die.

Scarface Claw (author)2013-08-22

Fantastic, looks like something from the desk of Santiago Calatrava . If only UK planning laws would allow such a thing....!

rasomu (author)Scarface Claw2013-08-25

No way, if it was Calatrava's should have cost more than his first impression and will fall down in less than five years.

I live in Valencia and the city or arts and sciences is an example of how this man works.

Scarface Claw (author)rasomu2013-08-25

Really? Wow. I've never seen his work first hand but studied his sketchwork closely at university.

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