I'm wrestling with a consideration regarding how to think about the angle of the step edge in relation to the center of a spiral staircase.
I'll attempt to illustrate the different options I'm contemplating with three images below.
Option 1 has a line whose extension cuts through the center of the spiral.
Option 2 is instead at a certain distance from the center of the spiral. If this distance is set at 50-60mm, it can correspond to approximately how it looks on a spiral staircase with a central pole of 100-120mm in diameter. This design increases the tread area at the inner edge of the staircase, is favorable for strength, and is likely necessary if building a tight spiral staircase.
Option 3 is an exaggeration of the reasoning in option 2 to clarify what I mean.
Besides the properties I mention above, it presumably also affects the feeling of walking on the staircase.
The question is which is the "optimal" choice if considering walking comfort. Maybe it's a matter of preference, and then it's obviously difficult to answer, but that is my question. It's about a basement staircase, but the laundry room is in the basement, so it will be used daily with a laundry basket in hand.
I hope someone has some wise perspectives on this.
I'll attempt to illustrate the different options I'm contemplating with three images below.
Option 1 has a line whose extension cuts through the center of the spiral.
Option 2 is instead at a certain distance from the center of the spiral. If this distance is set at 50-60mm, it can correspond to approximately how it looks on a spiral staircase with a central pole of 100-120mm in diameter. This design increases the tread area at the inner edge of the staircase, is favorable for strength, and is likely necessary if building a tight spiral staircase.
Option 3 is an exaggeration of the reasoning in option 2 to clarify what I mean.
Besides the properties I mention above, it presumably also affects the feeling of walking on the staircase.
The question is which is the "optimal" choice if considering walking comfort. Maybe it's a matter of preference, and then it's obviously difficult to answer, but that is my question. It's about a basement staircase, but the laundry room is in the basement, so it will be used daily with a laundry basket in hand.
I hope someone has some wise perspectives on this.
I usually do as in option 1.
Does the step width really increase on the inner edge in option 2? Doesn't it just result in an inward shift? I think it's mostly a construction-related issue if there's a slender central pole.
Does the step width really increase on the inner edge in option 2? Doesn't it just result in an inward shift? I think it's mostly a construction-related issue if there's a slender central pole.
I'm not 100% sure about the terminology regarding the step width. But in the extension of the foot, there is more to step on if the step doesn't cut the center. However, this extra surface can be added both at the front and back of the step, and in a classic spiral staircase, the step's line meets the tangent on the center rod both at the front and back. So you always get at least the diameter of the rod as "tread depth."
If both the front and back edges were to cut the center of the rod on a spiral staircase, it would be about 1-2cm likely.
So it's definitely necessary to have an offset then.
But in my case, I would get 70mm at the most if I aimed both the front and the back towards the center, and that feels unnecessarily little even if it holds.
What I'm mainly after is whether there's a desired feature in having an offset.
I can imagine that it's easier to move your feet in the continuous curve that a spiral staircase has if there is a certain attack angle on the steps.
Am I incomprehensible?
If both the front and back edges were to cut the center of the rod on a spiral staircase, it would be about 1-2cm likely.
So it's definitely necessary to have an offset then.
But in my case, I would get 70mm at the most if I aimed both the front and the back towards the center, and that feels unnecessarily little even if it holds.
What I'm mainly after is whether there's a desired feature in having an offset.
I can imagine that it's easier to move your feet in the continuous curve that a spiral staircase has if there is a certain attack angle on the steps.
Am I incomprehensible?