Medeek Wall Plugin
-
In my UK jurisdiction, and I suspect many more, you are not allowed 'winders' but 'tapered treads'.
The calculation of the dimensions is convoluted.
The minimum 'going' is 50mm [2"] and any tapering tread at the centerline must have a 'going' measured square to the nosing equal to all the other non-tapering treads.
For non-domestic wider stairs the measurements are taken measured in from the sides - about 1/3 each.
The 'going' is not the 'tread' dimension - the overhang of the nosing is taken off the tread size, so it's the 'plan' dimension.
When you get to anything other than a simple staircase it can become very complicated to 'automate'.
In the UK a helical stair [aka 'spiral'] even has a set of alternative British Standard staircase rules which differ significantly from the usual stair Building Regs - you need to tell the local inspector which one you're using otherwise you could fail.
I've mentioned before about the handrail requirements in the regs to extend 300mm [12"] beyond the top and bottom nosings in many situations, and the landing's going the be 300mm longer than the stair width.
Also, staggering the nosings by one going as the stair turns at a half-landing [or top] means that the handrail transitions smoothly without any need for a vertical portion to make it work... -
for some reason, many "metric" countries are using different building codes and material sizes from the others. whenever i start a studio design for someone - first check - get all the building codes and material sizing for that country established before beginning the actual design work. early on (~20 years ago) i made the mistake of assuming all metric countries were "standardized"... then after doing all the construction docs, during review the builder pointed out all the wrong dimensions on the materials, code-prohibited practices or confused one etc etc... needless to say another 3 weeks to fix it all...
Advertisement