A reader's Stairs question: Stair rule?

Christopher E.   from   Booyal (Pop approx 100) , Australia,   has kindly sent in this Stair rule tip.

Bill,
I just found your website and I am finding it full of useful info and tips.

Looking through the section on stairs I was reminded of something that I got from my father and have used on more than a few occasions.

Essentially it is this; To setout a staircase that is comfortable to walk (or indeed climb)up you follow this formula.

Rise(in inches) X Run(in inches) = 66inches.

Note that this formula does not readily translate into metric without first converting to Imperial and then converting back to metric.

If you are building say a set of steps using a single course of standard brickwork (86mm or 3.39 in) as risers then to make the going "comfortable " it should be

66 in /3.39 in = 19.47 in or 495mm,

a little over two brick lengths.

Have a fiddle about with a few different permutations such as ladder rungs and standard staircase dimensions.
Cheers
Chris
Reformed commercial builder and more recently reformed pig farmer.

Bill's reply

That formula struck a chord with me, I am sure I have seen it before.

I checked in a couple of my old text books and couldn't find it though, so I guess it may go back to my days in Pommie land.

It certainly works and is a great rule of thumb.

Of course these days of the BCA we have to watch ourselves for giving out false information. That's why I have to plaster the site with warning notices.

So to cover my back I really should do something like the warnings on the first home brew packs we used to get. From memory they went something like this:-

"Australian laws prohibit the making of beer over 2.5% alcohol content. "(and then it told you how much sugar to add to make it that strength)

"HOWEVER.. if you are outside the jurisdiction of Australia:use..." (and it goes on to tell you how to make full strength beer).

P.S. Chris, do you find that your current associates are more pleasant to work with than your former ones?