For a stair with the setting Break Mark Position: Floor Plan Cut Plane Height.
I expect the break mark to be drawn in reference to the FPCP of the view so that if the entire stair is placed below the FPCP then there will be no break mark. And this is what I get if the stair is within one story and have a view of the story above.
However, this does not seem to work if I place a stair entirely below the lowest story in a model. As the entire stair will be below the FPCP I don't expect there to be a break mark - yet there is.
If I add a lower story (regardless of height) it will be drawn correct (without break mark) on the story above. If I elevate the stair so that part of is within the range of the lowest story but below the FPCP it will be drawn correct (without break mark) at that story.
Am I missing something or is this a limitation or a bug? Running AC 25.4013.
Here is a illustration of the issue. The three stairs have the same setting and the plan view is from the ground floor. I expect the one in the middle and the one the right to be drawn without a break mark as they both are below the FPCP of the ground floor. But this is only the case for the middle, the right (which is placed completely outside the range of the lowest level) is drawn with a break mark. The break mark seem to be placed as if the stair was placed with zero offset from ground floor.
My guess is that since the stair to the right does not physically intersect any stories it doesn't have any Relevant Story which in turn breaks something in the calculation of the break mark position.
In this case the only purpose of such a story would be to ensure the correct display of that stair (and any other element that might suffer from the same limitation/bug) - that would be the definition of ad hoc.
Not only don't I want another story to place the stair in - I obviously don't need another story to place the stair in as there is no issue regarding the placement.
The issue here is an element not displaying as expected given its settings. The expectation might be wrong but otherwise it's either a limitation or a bug. If it is a limitation there should be some indication of it. If its a bug it should be investigated and fixed.
We’ve just found a similar issue with the Rails tool. A handrail that spans multiple levels (like a multilevel fire stair) doesn’t respect the display settings for “above relevant level”. We’re having to insert a dummy level above it so it doesn’t show up on roof plans.
I don’t recall this being an issue previously in AC24/etc, but we haven’t had a chance to go back and test.