Layout for spiral staircase

[BCsaw]

Does anyone have the layout to approach building your own spiral staircase?

Specifically need the math to figure out the necessary treads, their size and position of the entrance and top landing.

I want to build one out of metal.

Any help would be appreciated.

[shinnlinger]

You may want to see if there are any building regulations surrounding them in your area.   Depending on the space you have, it can be difficult to get sufficient width on the inside tread. 

[shinnlinger]

The math for number of treads is the same as regular stairs.   Take your total height and divide by your ideal stair rise, say 7.5 inches and adjust from there. 

The width of your tread will be dependent on the width of you opening and center  post.   Say you have an 8 ft opening and an 8inch post.  Your tread would be 48" minus half the post for 44" wide tread.   

[shinnlinger]

Will these be the only stairs serving that floor?   Even if code allows them, moving a king size bed up a spiral staircase can be tough.   If you have acess to larger diameter pipe, you could modularize your build by using two pipe sizes that fit snugly together.   Use the narrower one for your post and cut the larger one at the lengths you need your risers to be.   You could them weld your treads and brackets on each riser in the shop and then slip them on the center post at install time and adjust your entry and exit angle as needed.   

[BCsaw]

These stairs will access the loft in my wood shop. I figured that they would same some floor space and also look cool. The loft will be open, so large objects could go up that way. I was going to use a ladder, but stairs just seem safer.

I was thinking about the modularized design. That would certainly speed up assembly. ;D

Code says 7 7/8" maximum rise for each tread. 7 1/2 seems reasonable.

Thanks for the comments.

[shinnlinger]

What is your total rise and we could calculate your exact riser height

[Magicman]

 

 
Make it look like this and it will be super cool.   ;D

[Don_Papenburg]

The inner tread width is not as important as the walk line (usually the center line,but at least 12" from center post) should be to the minimum code will allow.
Try several  widths of three steps high to see what is comfortable for you as you walk down. Going up is easiest .  Work your walkline on what you find to be most comfortable.