how to do a stair like this?

[Anonymous]

Hello, I have to do a stair like the one in the right part of the attached pic. The area marked with red must be 0, thus the flight of the stairs being aligned. I want to use regular Archicad library parts not customized stairs and I have to make the stair in one piece, not 2 stairs and a slab. Which option I have to check/uncheck because Archicad won't let me to do this.

Thanks!

[Anonymous]

Zero depth returns are not possible with Stairmaker. It seems you are already aware of the other options such as:

1. Just make it as small as possible if that's close enough for your present purpose.

2. Build the stair from separate flights of treads.

3. Use Archistair or the Cadimage stair tool.

4. Build it out of parts.

As far as I know this is what you are stuck with. It is an unfortunate limitation in Stairmaker. In their defense it is a tricky detail to work out (particularly in wood trimmed carriage stairs) and it is illegal for public/commercial use in the states so the need to model this condition is rather rare at least over here.

[Anonymous]

Thanks for the answer. This concrete stair is for a private house and must fit in a relatively small space. As a matter of fact, in my country this kind of stair is just discouraged, not illegal (still), but who knows in the future.

[Anonymous]

"Matthew Lohden"...and it is illegal for public/commercial use in the states...[/quote wrote:


I hate to go off topic here but could you explain why it's illegal? I don't know and I'm curious if you don't mind.

[David Maudlin]

Matthew wrote:
In their defense it is a tricky detail to work out (particularly in wood trimmed carriage stairs) and it is illegal for public/commercial use in the states so the need to model this condition is rather rare at least over here.

This condition is very common in residential projects, so should not be so hard to accomplish with this tool. The continuous handrail on the inside of the stair is the tricky part.

David

[Anonymous]

David wrote:

Matthew wrote:
In their defense it is a tricky detail to work out (particularly in wood trimmed carriage stairs) and it is illegal for public/commercial use in the states so the need to model this condition is rather rare at least over here.

This condition is very common in residential projects, so should not be so hard to accomplish with this tool. The continuous handrail on the inside of the stair is the tricky part.

David

Yes, I had to work around this quite often back when I was doing residential work. The rail easement is the trickiest bit, which is most easily solved with a newel post, which as I recall is not supported in Stairmaker. I remember one project I did with Rill & Decker where I had to stick build the entire staircase.

Even worse is when you need a winder with zero returns. Of course these are for existing conditions only since they are no longer legal to build even for residences (at least in every jurisdiction I've worked in).

[Anonymous]

zeropointreference wrote:

Matthew wrote:
...and it is illegal for public/commercial use in the states...

I hate to go off topic here but could you explain why it's illegal? I don't know and I'm curious if you don't mind.

I'm not really a code expert so I don't know the details, but I assume it has to do with making an easy transition from stair to landing to reduce tripping and falling hazards. The zero return does make for a tight stair and it makes sense to me that one would prefer not to be navigating such a stair with a random assortment of other folks entering or leaving a public place, particularly in a hurried or panicked manner. In residential applications where stairs are typically used by only one person at a time (or two or three who know each other) tight stairs aren't such a problem.

[Anonymous]

I do mostly revamps or renos for small commercial or residential. A couple of times I had to do stairs or deal with a project that has stairs in that configuration. I have one instance in particular in mind where there was a high capacity exit stair from the top floor of a nightclub down to the front lobby that had its landing in such a configuration. The building wasn't that old so it made me wonder if maybe it was missed by the city during review or maybe it is a legal configuration.

The reason I wanted to know is I do occasionally design stairs but they've been small projects and mostly straight. My concern is I'm not worried so much about the code reviewers as I am wanting to make safe stairs regardless whether the code allows it or not. It's interesting what you pointed out and it's something I'll keep in mind for the future.

Thanks.

[Anonymous]

In Stair Maker:
1. Go to Structure ans landing settings
2. In Structure type choose the far right option
3. Now go back to Geometry and flight settings and you can use zero values!

The bad guy is the Nosing size on the front.