Staircases

[JFC]

I only get about one a year so i normally mark out the rise and going in my workshop and work the angle out by physically putting the strings in place . I know there is a way of working out the angle so i don't need to do this but i cant remember what it is Any tips ?
The rise is 2608mm so 186mm per rise and the going is 2820mm so 235 per tread with two winders and two treads down , the rest is a straight flight .

 

[SketchUp Guru]

If I followed your numbers correctly, which I admit I may not have, it looks like about 38.4°. I drew it in SU and made it tell me the angle.

 

[JFC]

Thanks Dave but do you know how sketch up worked it out ? I know there is a table that gives the rise and going=* and it was posted on here but my search on staircases only has four pages

 

[SketchUp Guru]

SketchUp did it by measuring the angle between a horizontal construction line and one I drew connecting like corners of a couple of the treads. I'm sorry I can't point you to a table that tells you. You could calculate it with a bit of trig. The tangent of the angle is equal to the rise over the going.

 

[JFC]

Its the turn that gets me , but then i suppose if the centre of the winders are the same as the going then its like working out a straight flight .So adding the winders and two treads makes the going 4150mm but doesn't alter the overall going of the treads excluding the winders .........
Nope thats not working out Grrrrrrrrrrr 13 years since i was taught this stuff ! Looks like moving machines and mocking up the area to get it right as my brain is now hurting .

 

[Shultzy]

The formula is

tan a = rise / going

tan a = 2608mm / 2820mm

= 42.76deg

 

[engineer one]

forgotten your trig have you jason???

vertical and depth will allow for the angle.
"square on the hypotenuse is equal to the square of the other two sides.
gawd that came from a long way back :lol:

so using your calculator. lets say 2metres high and 1.5 metre front to back. so you 4 +2.25 = 6.25 so whats the square root??? 2.5
so strike your arc of that length and then measure with a protractor!!

will check on design cad for you and let you know too.

paul :wink:

 

[engineer one]

ok a quick check, and as was said for the overall dimensions the angle is
actually 47.2 degrees, but when laying out the steps to length and depth, the actual angle of the mid part is 38.1 degrees

hope this helps too. :?

paul :wink:

 

[mel]

engineer one
you took the words right out my mouth :^o :^o
jason im the same as you with the hands on approach {laying it out on the floor, so to speak}
normally around 42-43 degrees , except in older terraced houses
ive respindled a lot of staircases

 

[JFC]

Forgotten it , i cant even remember learning it :lol: I have it all written down somewhere but with all the new regs and keeping your tax returns up to date etc who has time to actually earn a living ! Sorry for the mini rant :shock:
Edit : Paul i think the regs need the staircase to be 42* max .

 

[engineer one]

now you want to make a living too?????? :twisted: :twisted:

paul :wink:

 

[JFC]

The formula is

tan a = rise / going

tan a = 2608mm / 2820mm

= 42.76deg
_________________

I think that was what i was looking for but my brain is fried right now .

 

[Barry Burgess]

Jason see if this Ausie site will help - its all the stair calculation with pictures
http://www.blocklayer.com/Stairs/
Your brain should be able to cope with this
barry