Interesting questions that I cannot find an answer for. PLZ help
Question from PPI:
You are showing 18' ramp (using the max accessible slope) from the exterior of the building to the interior, how many treads would be in a stair if you were to use stairs instead of a ramp?
Would it be 1, 2, 3 or 4?
The question boils down to the height difference between exterior and interior: is it 8" ( accounting for 2 5' landings) or 18" (accounting for no landings)?
Thank you for your time and efforts.
-
Marco,
Hi. What do you mean? The stairs would go from exterior to interior, 18". The stair doesn't need landings on the same level as the ramp (or any actually, and neither does the ramp). So we'd need 3 or more risers. 3 @ 6" each, or 4 @ 4.5" each. 3 risers = 2 treads, or 3 treads for 4 risers. Does that make sense?
Rebekka O'Melia, R.A., NCARB, B. Arch, M. Ed, NOMA, Step UP ARE 5.0 Courses
-
Hi Rebekka,
Thank you for your reply. I meant that should we count the landings as part of the ramp? if so, we will have 1 landing (5') at the start of the ramp and 1 at the end. Then we have 8', which is 8" of actual height difference between the outside and the inside. so the stairs have to get us 8" up only. Which means 2 risers and 1 tread. But if we did not account the landings as part of the ramp, we have 18" difference between the inside and outside, which translates to stairs with 3 risers and 2 treads. (Which I think is the right answer)
-
Marco, on the ARE exam there would likely be a dimensioned drawing so you could see if the ramp length included landings. In the absence of a drawing, there would be an explanation in the text as to whether the ramp length included landings at either end (or, in some cases, intermediate landings). Know that you are on the right track and are having trouble because there is not enough information given (assuming you transcribed the question as it is written in the study material you are using and didn't leave anything out). You obviously understand the concept and you have my encouragement to ignore this question. Good luck. --Michael Ermann, Amber Book creator.
-
I agree with Michael - this kind of a question should provide either a drawing or a more detailed description so you're not guessing about whether the landings are included or not.
Hopefully you don't get a question on the ARE like this but if you do, I'd assume that an 18' long ramp at maximum accessible slope means exactly that - a sloped walking surface that rises 18" total. 'Ramp' is defined in both ANSI A117.1 and the 2018 IBC as (paraphrasing) a sloped walking surface with a slope of greater than 1:20. Landings, by that definition, are not part of a ramp, since landing slopes are limited to 1:48 max.
Chris Hopstock RA
Black Spectacles
ARE Community -
Michael & Christopher, I truly appreciate your time and efforts. Thank you for your reply. Unfortunately, the exam did not provide a drawing or any other info, but I totally agree, that since no further info was provided that we should assume the 18" is the height difference between interior and exterior.
Please sign in to leave a comment.
Comments
5 comments