Bricks, Masonry, Asphalt and Concrete - Rise and Run for steps
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timkins
04-30-06, 04:59 PM
PLEASE SOME HELP HERE! I finally have the exact measurements for my steps. These will be a semi circular set of steps. The difference between the landing and the top step will be 88". I figured the number of steps should be 13. The way I have it figured is the rise will be 6.75" (88 divided by 13 = 6.75").The inside dimension of the semi circle is 209" and the outside dimension of the semi circle will be 249". Therefore the run for the inside of the semi circle should be 16" (209" divided by 13 = 16") and the run on the outside of the semi circle will be 19" (249" divided by 13 = 19"). Am I in the ball park here are my figures and dimensions way off.
XSleeper
04-30-06, 05:33 PM
According to my calculations (I don't claim to be a math wizard), if you have a semi-circle (half a circle) where the inside arc is 209" and the outside arc is 249", the radius of the inside arc would be 66.5", the radius of the outside arc would be 79.25, meaning your stairs would only be 12.75" wide. Sounds like a pretty narrow staircase to me. ;)
How wide of an arc are these stairs supposed to cover? In other words, what's the horizontal distance from the inside corner at the bottom of the stairs to the inside corner at the top of the stairs? (the diameter of the semicircle that the stairs will circumvent?)
Only problem with this is that I didn't take into consideration the rise of the stairs! I'll continue to work on this. Give me something to do on a Sunday night. LOL
How wide of an arc are these stairs supposed to cover? In other words, what's the horizontal distance from the inside corner at the bottom of the stairs to the inside corner at the top of the stairs? (the diameter of the semicircle that the stairs will circumvent?)
Only problem with this is that I didn't take into consideration the rise of the stairs! I'll continue to work on this. Give me something to do on a Sunday night. LOL
Pecos
05-01-06, 04:30 AM
If these are concrete steps, don't forget to account for slope when determining the height of your risers. You don't want water ponding on your steps.
Pecos
Pecos
XSleeper
05-01-06, 07:29 PM
Ok. I've figured this several times. And I guess I have a question regarding how you came up with 209 and 249.
What I did first is drew it as 2 circles. 209x2 being the circumference of the inner circle and 249x2 being the circmference of the outer circle. This allowed me to determine the diameter of the inner semi-circle as being 133" and the diameter of the outer circle as being 158.5. Subtract these two figures and you get 25.5, then divide that by 2, and you get 12.75", which would be the distance that separates those two semi-circles.
Then I wondered if you gave two dimensional measurements (as if you were looking down on the steps from above) or three dimensional measurements (such as the length of a helix wrapped halfway around a cylinder).
I also wondered if your steps are supposed to be 40" wide, since that is the difference between your measurements (249-209)? If that is the case, then if your inside semicircle is 209, your outside semicircle would actually be 334.66 in length, which would mean the short side of the steps [inside] would be (209/13=16.07) and the wide side of the steps [outside] would be (334.66/13=25.74).
What I did first is drew it as 2 circles. 209x2 being the circumference of the inner circle and 249x2 being the circmference of the outer circle. This allowed me to determine the diameter of the inner semi-circle as being 133" and the diameter of the outer circle as being 158.5. Subtract these two figures and you get 25.5, then divide that by 2, and you get 12.75", which would be the distance that separates those two semi-circles.
Then I wondered if you gave two dimensional measurements (as if you were looking down on the steps from above) or three dimensional measurements (such as the length of a helix wrapped halfway around a cylinder).
I also wondered if your steps are supposed to be 40" wide, since that is the difference between your measurements (249-209)? If that is the case, then if your inside semicircle is 209, your outside semicircle would actually be 334.66 in length, which would mean the short side of the steps [inside] would be (209/13=16.07) and the wide side of the steps [outside] would be (334.66/13=25.74).