Stair Calculator?

[barrie.sharp]

I want to make sure my stairs meet building regs and I thought that the stair calculator would do the trick. I thought I understood what was needed but the results say otherwise. For instance, I need a minimum going of 220mm, a maximum rise of 220mm and a maximum of 42° incline. Does this tool actually achieve this or is it just 'best fit guidance'?

[patricks]

The stair calculator is geared toward the requirement that says 2 risers plus 1 tread (going?) cannot exceed 25 inches. I thought that was in the IBC but I'm not seeing it and I can't remember where that requirement is.

What code you guys under in the UK? I'm not sure if there's a way to automatically calculate it with a maximum slope angle requirement. In the US the maximum stair slope permitted is 32.47° (based on a maximum riser of 7" and minimum tread of 11"). IBC codes do not contain a hard maximum slope or angle dimension for stairs.

[barrie.sharp]

In the UK, we use Approved Documents for The Building Regulations. Part K - Protection from Falling describes requirements for private stairs under Section 1 (See attached if interested). They allow a little flexibilty but if you stick to the bare requirements, the stairs would end up at 45° so there is a footnote stating 42° as a maximum.

It's interesting to see the differences in regulation. It is a shame that the stair calculator is restricted to only the needs of US customers. I am sure it wouldn't take much to expand its function so I should put in a request I suppose. In summary then, there is no way to get the results needed for UK use. Oh well :)

[patricks]

Well if you just set your stair type to have a minimum going to 244mm and maximum riser to 220mm then you'll never be over 42° :)

[barrie.sharp]

How true! Quite often we are space saving but I could create a seperate type. Cheers:)

[patricks]

Or you could go the other way 'round and set minimum going to 220 and max riser to 198 and you'd still be at 42° However that would still take up more length than the 244/220 stairs. You can check the math (I'm converting myself to mm, I just can't think that way). :p

[barrie.sharp]

I hear ya, feet and inches hurt my nogging. We should all work in Smoots and Ears to create a common international standard! ;)

[patricks]

heh it's funny because I've been driving nothing but Honda and Toyota vehicles for the past 15+ years and can do pretty much all mechanical work, and everything on those cars is metric. I don't even own any imperial-sized wrenches! Yet I still have to think in my head "okay 25mm is about 1 inch so 12mm is.... pretty close to 1/2 inch"

But then looking at a metric architectural drawing or industrial machinery diagram with nothing but MM numbers all over it just makes my head spin.

[barrie.sharp]

lol. In the UK, alot of mechanical is imperial measurements. What's more, we measure height in feet and inches, weight in stones and pounds. Someones height in mm completely throws me but likewise, I will measure a building in mm.