Stair and tread design.

[truckdesigner]

Our Australian Standard AS1657 "Fixed platforms, walkways, stairways and ladders" stipulates some pretty strict rules for tread spacings (I am sure most worldwide do).

ie.

"All rises and goings in same flight of stairs shall be of uniform dimension +-5mm.
Each rise shall not be less than 150 mm nor greater than 215 mm.
Each going shall not be less than 215 mm nor greater than 305 mm.
The product of the going multiplied by the rise, in mm, shall not be less than 45000 nor greater than 48000.
Max slope is 45 degrees and min slope is 26.5 degrees."

I am currently designing a stairway with a height of 2900 mm. It has been a few years since I have done one of these. Does anyone have a procedure, shortcut, or even just some tips on how to do this quickly and efficiently?

It can get quite messy...

Regards.

 

[apsix]

use 250 going x 190 rise as your starting point; adjust to suit your height difference.

 

[paddingtongreen]

Try 200mm riser. 2900/200=14.5 risers no good. Use 15 risers.
2900/15=193.3
45000/193.3=233
48000/193.3=248

15 equal risers with a going between 233 and 248

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[weab]

Agree with apsix, 190/250. That's our preferred.

 

[csd72]

No the Australian code is not that strict, try using the british standard for these things.

I thought that the BCA had a table for this type of thing, could be wrong as it has been a while.

 

[truckdesigner]

Thanks folks for your assistance. My apologies for the delay. Clearly there is no hard and fast rule for this one - even for the gurus.

Paddigntongreen your method seems the most foolproof - I shall pursue it. The 190/250 seems a bit vague...

Regards.