# Forum Home Renovation Stairs, Steps and Ramps  External Stairs: width question

## Halfie

Quick question- 
I am constructing some external stairs off a deck with steel stringers.
Is there a minimum width they have to be?
Right now I have 855mm but I can rejiggle if necessary.
Just want to make sure I'm not bending the rules!
Thanks.  :Smilie:

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## ringtail

just checked the BCA. As long as it is not a spiral or uses tapered treads, there is NO measurement given as a minimum. Ive looked at it for an hour, and while there is a diagram that shows the width, there is no measurement and no reference to it at all. Go figure.

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## danielhobby

commonly acceptd that you should try for a minimum of 900 to a metre between handrails or handrail to wall.i specialise in spiral stairs only so am not an xspurt but have done so for thirty years and seen a few .good luck

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## ringtail

Strange one. Ive seen them anywhere from 700 to 3000 wide, but agree around the 900 - 1200 is pretty good. I dont see a drama with 855, bit wider would be nice.

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## r3nov8or

Just think about that TV ad where the guys take all sorts of things apart to get the fridge up stairs  :Smilie:

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## Halfie

Thanks for looking it up ringtail and for your reply also danielhobby. 
After much trolling on the net last night I did come up with this- 
"clear opening, 850mm minimum, 900mm preferred, 1200mm will allow easy movement of furniture and addition of a stair lift" 
That was taken from-  Build for Life - Stairs 
That is aiming at an internal stair but I think I would be safe applying it to my example. I have good access from other parts of the house, this stair is just access down to the backyard from the deck.

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## Blocklayer

> That was taken from-  Build for Life - Stairs

  The diagram 12.4 on that page shows riser 170 to 180 and going 150 to 165. 
Thats steeper than 45 degrees  :Shock: 
A bit 'ladderish'. Maybe its for athletic Hobbits with really short feet? 
:

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## ringtail

All of which are illegal. 2 rise plus the go must be min 550 max 700. Min go is 240 mm, max go is 355 mm, min rise 115 mm max rise 190  on all stairs except spirals.

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## 2x4

> min rise 115 mm max rise 190

  Do all risers need to be the same? 
I have a floor I have just raised to match existing.(80% complete) All risers are 180mm with the top two treads to have a rise of 160mm each. These 2 will be a 45 degree winder style. 
Please dont tell me I'm about to build a death trap. :Redface:   
.

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## mac10

> Do all risers need to be the same? 
> I have a floor I have just raised to match existing.(80% complete) All risers are 180mm with the top two treads to have a rise of 160mm each. These 2 will be a 45 degree winder style. 
> Please dont tell me I'm about to build a death trap.  
> .

  I hate to be the bearer of bad news, but all risers should be of equal height (legally) I know it doesnt sound like much but I think you will find that even a small difference of 5-10mm can trip you up. How long are your stairs? Im assuming you weren't planning on replacing the stairs?

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## ringtail

Mac10 is spot on. All risers in the flight must be the same. If you had two flights, with a landing between, each flight can have a different rise but each rise in same flight must be the same.

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## 2x4

No I wasnt going to replace the stairs. 
Oh well. Looks like a bit more work than I hoped for.  :Doh:   
.

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## Compleat Amateu

Being in favour of saving working, even if you have to spend a bit to do so .... there is a mob in Brisbane (Scott Metals - Products) that fabricates good steel stringers to order, and have standard sizes readily available. 
I've used them, beats the hell out of thinking about rise, run etc. As long as you have the vertical dimension, the rest follows.  And they will manufacture non-standard stringers, I got one set with riser spacings 5mm less than standard to suit my particular situation. 
Probably other manufacturers in other States, but delivery is pretty cheap.

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## ringtail

Be very careful using these fabricators ( scotts included) as they have a standard rise which is 175 mm. Which is useless because when you put the 50 mm timber tread on the clearance between the treads is 125 mm which is right on the limit. Then the timber shrinks and the stairs are illegal unless you put little strips of timber under each tread to close the gap. If you order anything other than the standard rise the price is more than doubled with a huge lead time. 175 mm IMHO is to much anyway, 165 is much more comfortable.

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