Monolithic Concrete Stairs

[Arnel Aguel]

I'm trying to create a monolithic concrete stairs following this tutorial http://usa.autodesk.com/adsk/servlet/item?siteID=123112&id=3027322 however i'm not sure if it is just me or there is really a little bit of a problem with the tutorial. If you follow exactly the tutorial the upper end of the stairs will leave a gap from the upper level boundary of the stairs. If you set the Riser Type back to straight or incline instead of none it will also give you a very thin riser at the top most part. Any idea guys?

BTW, my requirement is actually a U shaped monolithic concrete stairs. I did try creating one following the above tutorial but it gives me an error message "A piece of boundary is too short to create a boundary on it".

I'm confused which part it is referring to.

[studioCJF]

Arnel

I had lots of trouble with monolithic stairs using the tutorial sequence.
I think it works fine for simple straight run stairs. but my problem was that mt monumental stair is "L" shaped with the treads of the stairs on the short leg twice as deep as those on the long leg. The stairs on the long leg are a typical 7"/11" riser/tread but the stairs on the short leg are 7"/22" riser/tread. (you know the kind of stairs that are hard to walk on because your rythm is all screwed :screwy: up). I tried making two stairs that mitered in the corner but with slanted risers the miter is close but not good enough for me...long story short now both legs of the"L" are the same.

I still wouldn't mind figureing that one out for the future though.

Clark
(see attached this is from part of my very first and only revit project)

[beegee]

If you set the Riser Type back to straight or incline instead of none it will also give you a very thin riser at the top most part. Any idea guys?

The riser type must be set to "None" for monolithic stairs. Use the align tool to align the upper edge of the stair with the upper slab edge. Note that for other stair types, the top tread is the floor edge of the level above. The last riser ends at the floor level.

To create a U shaped stair, firstly create a "dogleg" then edit it by deleting the bottom riser at the landing and add a riser at the top of the final flight. Fix the boundaries, to maintain a closed loop. Delete the outside landing edge and constuct an arc.

[Arnel Aguel]

The riser type must be set to "None" for monolithic stairs. Use the align tool to align the upper edge of the stair with the upper slab edge. Note that for other stair types, the top tread is the floor edge of the level above. The last riser ends at the floor level.

Beegee it won't work. After setting the riser type to none as per the tutorial and as what i've said it will leave a gap from the upper level boundary using align tool will not work. It will not move the stairs to align to the upper boundary.

[beegee]

Arnel,

Can you copy the file, purge, delete all other stuff etc and post it ?

[Arnel Aguel]

I just made a simple one for review.

Here is the file.

[beegee]

Arnel,

The gap you're seeing is because the top tread of all stairs is the floor level above. So the gap is the difference between the stair riser height and the slab thickness,( without an edge beam condition.)
This only happens with a monolithic stair, as this type of stair is defined without a riser, so there is nothing to close the 'gap'. But, of course, the "gap" doesn't really exist, since there would be an edge beam/ thickening to connect the reo properly.

If you were cutting a section through the stair lengthwise, you could use the 'cut profile' tool to draw in the edge condition. Otherwise, for 3D and elevations, you could use a sweep, as mentioned.

[Arnel Aguel]

Beegee, certain designs doesn't need an edge beam condition. Should it be that a basic and most widely used type of stairs like this be a simple process for a very powerful program? Drafting the edge beam condition to hide the gap is for me not the solution of the problem. Who knows one would be needing 3d for rendering.

I am not sure also if sweep will work as my requirement is actually a U-type concrete stairs.

[beegee]

Yes, monolithic stairs can be improved in Revit, and I expect they will be, but until then, just model a sweep or an extrusion, to create the closure between the stair and the slab, if you don't want a beam.

[Nic M.]

I use the following work arround fot monolithic stairs:

- draw the stair as usual
- in the properties:
- add 1 stair to the "actual Number of Risers"
- manualy calculate the new rise of the stair
- put this number in the "Top offset"
- OK now you get an message to add the correct number of treads
- strech the run to add a tread OK
- put the stair in possition

You now have a stair that connects to the upper level. BUT in the properties it reads 18 risers, while actualy there are 17. So look out.

I can post your stair back to clarify my bad english.
Let me know if this is usefull to you

[Arnel Aguel]

I've just also figured it out no need to calculate anything. When invoking the stairs command prior to drawing the run of the stairs go to stairs properties and check the actual depth value (which is automatically computed and in grey) and put the same value in the top offset that will do the trick.

However, this cannot be used in a U-type stairs it will result to an error and some unwanted result. As a work around for U-type stairs i just created the a floor slab for the intermediate landing then create two straight stairs going up and down respectively using the same process above.

[beegee]

Arnel,

If you increase the top offset distance, the number of risers will not be correct.

Nic,

I think this is not good practice, particularly in a multi user environment, where another user could create a stair schedule that would be incorrect without realising it. It also prevents the single user from creating such a schedule of course.

Surely its not that hard to model a partial riser at the top of the stair to close it ? Then everything works.

[Arnel Aguel]

Arnel,

If you increase the top offset distance, the number of risers will not be correct.

Yes i agree Beegee that the riser count in the model is less by 1 than the one in the property dialog box but at least this gives me a correct model of my stairs.

[Nic M.]

I spent to much time on the stair module and I think its a big issue for a next release.
I agree it's a bit of an ADT solution and certainly not to be used in a multi user environment but it gives a correct model.

lighting candles and praying to Madre Madonna for rel 6

Amen

[beegee]

Sorry guys, but the point escapes me :screwy:

The attached image is a correct stair ( plans, elevations, sections, schedules, the whole deal ) achieved with a quick in place extrusion in about the same time it would take to reconfigure the stair properities.

[studioCJF]

beegee

That's what I have been doing.
(see 2nd post in this thread)

But, how does one go about making a stair with deeper treads on one of the legs and get everything to miter correctly at the outside corner. I have done it with straight risers making 2 separate stairs using the tutorial method, but if the riser is sloped then you get a strange overlap at the outside corner.

[beegee]

Well, for mine, I'd be modelling that stair as an in-place family, using extrusions. Its a one -off special and its easier to do in place, rather than trying to get the stair dialogue to work in this case and join treads correctly, as you've found.