# circular staircase - Moved



## Ira (Mar 18, 2010)

I have built a semi circular stair case. I would like to close the treads and construct a skirt wall three inches above the steps to install the wrought iron railings on. I am having trouble making it work. Any help would be appreciated.


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## Birch (Jul 20, 2009)

*Slinky Tech*

Ira,

Do you want to build this 3” tall wall cap on the existing stairs? I’ll assume so.

To cap the stairs off at the nose of the treads, take the plan-view arc length of the semi circle as the run, and the FF to FF height as the rise, and calculate the arc length of the spiral at the stair nose, then figure the radius of the new arc length. This is the radius of the arc you’ll cut your ply-lam strips too (add wall thickness) that will be laminated together in place to create the cap.

I’d use three layers/plies of 1/2” CDX for strength. To bring the cap up to the desired 3” height, nail pre cut 1 1/2" taller cripple studs to the stairs risers (on the wall line), glue and attach the cap laminations to these studs as you go. The plies will be staggered slightly to make up for the plumb angle versus the square cut arc rips. You may need to allow for this in your wall width too. (slightly less)

It’s like stretching out a slinky.  

I hope that helps. Please post more pics when you get it done.


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## Warren (Feb 19, 2005)

Personally, I think I would cut back the existing steps and then build the wall next to the steps. Seems like trying to add on top with a crip wall/ plywood build up is gonna be difficult to secure and nearly impossible to keep plumb.


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## Railman (Jan 19, 2008)

It seems to me that it would be simpler, & look nicer, to just add finish tread ends to the existing treads, & install the balusters onto the finish (oak?) treads. Closing in the treads just complicates things. You can either add a stringer directly over the existing wall by doing 1/4" laminations, or just drywall right to the existing tread edges. The overlay finish treads offer a little cover to the drywall edges. LJ Smith, among others, offer Finish tread add ons.

Try Carolina Stair: http://www.carolinastair.com/Products/tabid/56/cat/10/Default.aspx
Go to #8074
Joe


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## BKFranks (Feb 19, 2008)

Why do you need to do that to run wrought iron railings?


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