A spiral stairway

[gduke2010]

Built this stair last sumer

[gduke2010]

The almost finished product

[rwest]

That's awesome, was the math tough?

[mreid]

That is some mighty fine craftsmanship right there! Great job!

Are the treads pegged or screwed together?

[Seahawk]

Originally Posted by gduke2010

M.C. Escher, paging Mr. M.C. Escher...

Nice!

[gduke2010]

Every 4th tread has a steel plate welded to the steel columns that you can see in between the plywood sheating. A spline is routed into the bottom of the white oak slab which the tread fits over. Each slab has a grove routed into the top and bottom and a wood spline fits between the bottom and top of the slab. The steel railing has a threaded bolt holding everything together as seen in the second pic.

It took a long time to build, like 4 slabs/day, and they were heavy. The steel workers did a great job on the railing.

We were wondering how strong the stairs would be but, everything is tied together and there is no deflection.

[gduke2010]

This is after 2 days work. You can see the steel column on the top slab that the flat 3/8 x 4" steel is welded to. That slab took the longest lining up the slab with the steel and routing the grove. It had to be a tight fit, no play or slop. I prefit the slab and PL400 premium on the steel and lifted the slab on to the steel.

[gduke2010]

This is a view from the top. You can see the holes drilled for the railing which holds everything together.

[Porsche-O-Phile]

Very cool - damn nearly impossible to get permitted anymore unfortunately. A huge pool of potential design awesomeness ruined by overzealous code officials and power-tripping building inspectors - and the ambulance chasers that enable both.

That's seriously nice work.

[Craig T]

Just awesome! I'd consider a move to a two-story house just to have that I'm my house. Seriously.

[gduke2010]

Might be going to Napa Co. for a cabinet install in the near future.

These are the office cabinets

[Charles Freeborn]

Outstanding!

[mreid]

Fine woodwork like fine automobile craftsmanship are my drugs of choice.

Simply outstanding!

[Moses]

Beautiful cabinetry and the staircase is MAGNIFICENT!! You're an artist.

[juanbenae]

WOW! as a former carpenter that is very, very impressive! was there computer aided design incorporated? or as previously asked did you do the math on a 2x8 with a carpenter's crayon?

if I could wear two hats they'd both be off to that sir!

[juanbenae]

where the treads go into the wall have you built pony walls with the treads acting like header with kingstud support, or just a framed radius stuff shear walled in? so impressed! id love to see a shot of how you support the treads at the wall

[gduke2010]

Yes, they go into the wall and sit on a 6"*8". We used a template that you can see bellow the stairs in one of the pics

[gduke2010]

Originally Posted by juanbenae

where the treads go into the wall have you built pony walls with the treads acting like header with kingstud support, or just a framed radius stuff shear walled in? so impressed! id love to see a shot of how you support the treads at the wall

The treads were cut in our shop. One the jobsite we laid out the raidius on the gyp create floor and laisered to the slabs and worked off control line for the heights. The treads were off a tiny bit on heights like with in 1/6th or 1/32 nd but, big. Good thing they weren't too small. So, some had to be milled down. The top of the top tread had to be 3/4" bellow the second floor finish floor .

[gduke2010]

In pic #2 you can see the flat piece of steel that the welders welded to the steel column. Also, there are 2 holes in the steel where the lag bolts fasten the steel to the slab