Curved Stair Help Needed

[Anonymous]

Hi, folks, can someone help me make some curved stairs? I'm getting close, but not close enough.

I've got a 30' circular atrium that goes through four floors of the building, and I want a curved stair that ascends less than half the perimeter, and outside its outer edge, requring walking to the next flight, so that each floor's stair is a mirror image of the one below, but so that they don't meet in plan. In other words, each flight will be less than 180 degrees. I'm still playing with the design, so I don't know by how much exactly.

I've been messing around with the angle in Stairmaker, and I'm getting close, but I just can't get the stair to align with the edge of the opening in the slab. I've tried doing it with Stairbuilder, too, but something about the settings I'm using is crashing that and not producing any stairway. Or was it Stairbuilder that allows setting the angle? I can't remember. Either way, it's not working very well.

I'm afraid I really don't know very much at all about stair design in the first place, and coupled with the cryptic selections in Stairbuilder in particular, I'm at a bit of a loss for an easier way to do this - and to ensure proper cuts out of the slab or additions to it, or whatever is needed in a situation like this.

TIA for any assistance.

Wendy

[Steve Jepson]

Use the "Create Stair Using Selection" tool. See "Creating Custom Stairs from Drawing Elements" in the Help menu.

[Steve Jepson]

Like this ?

[Anonymous]

Steve wrote:
Use the "Create Stair Using Selection" tool. See "Creating Custom Stairs from Drawing Elements" in the Help menu.

Thanks, Steve. I didn't know about that. I've never worked with fills, though, and can't seem to get the nice neat polygons that you've got. They turn out like pie wedges, totally odd shapes, or don't take at all.

Wendy

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[Steve Jepson]

Can you post some pictures of what you are trying to do?

[Anonymous]

Steve wrote:
Can you post some pictures of what you are trying to do?

If my Internet connection will keep connected - it's been a real problem this evening <sigh>. Please ignore the rest of the mess on the screenshot.

Your second diagram is the basic plan, but with the two stairs on separate stories, and with the inner circle actually a hole in the slab.

Wendy

[Steve Jepson]

Something like this?

[Steve Jepson]

in 3d it looks like this.

[Anonymous]

Steve,

Yes, exactly, except with the stairs on only two sides, so that one has to walk between the flights, and facing the other direction. I suspect the atrium is going to shrink, though, because I'm already having a hard time fitting everything else in around it.

Is it possible to extend at least some of the treads so that they are deep enough to require a couple of steps, or potentially even incorporate a short landing or two part way up, so that the progression from one floor to the next is lengthened and slowed?

There's also going to be a couple of other twists. Once I finalize the size and exact placement of the atrium, it's going to taper somewhat from ground level through to the roof, where it will be capped with a small glass enclosure and form part of a roof garden, so each stair will have to be a bit different, and somehow go from a wider opening below to a narrower one above. Unfortunately, not being very good at this yet even with simple stairs, I have no idea how to deal with the landings in a situation like this.

Then, if I can figure out how to do it, the slabs will be stairstepped around the opening in the same sort of taper, sort of like crown molding, but integral to the slab.

The project is a Buddhist temple, and part of the idea with the atrium and stairs is to create a sense of journey, pathway, and seeking enlightenment, while architecturally incorporating elements of the stupa, which Buddhists walk around and up in a similar way as part of their meditation practice.

Thanks for your help; I really appreciate it. I wish I could figure out how to do this myself, but the procedure is just escaping me.

Wendy

[Steve Jepson]

I must admit that I don't really understand exactly what the stair needs to look like but I am sure that ArchiCAD can make any stair you want. As far as changing the width of treads and progression of risers,

I am afraid you may be in trouble with blind monks and building inspectors.

There is a maximum number of risers you can have with out a landing, (12' max I think) and the greatest variance between riser heights and tread widths in a stair can not exceed 3/8" (for residence) something similar for commercial. An inconsistent stair is an accident waiting to happen. The smallest change can make you trip.