calculating outdoor steps/stair size

[thetyreman]

hello, I am wondering where to start with some outdoor steps, I feel a bit overwhelmed but I think I can do it.

I have agreed to make them for my parents, first as a temporary prototype version out of pine, then I will make a better version later probably out of oak and with proper joinery.

It's been a challenge trying to work it all out with the design,

the reason I'm making them is my mum is about to have a hip replacement next weekend so she'll probably be in for about 5 days, hopefully I can make something before then.

I have attached some drawings I've done and photos all taken on my phone so excuse the poor quality.

The steps will have a rail as well attached to the right hand side of them.

What are the accepted standards with stairs or steps? what's the best way to calculate it all? cheers, Ben.

 

[thetyreman]

pics

 

[MikeG.]

I'd be very careful of outdoor steps in timber, Ben. They end up being really slippery in winter, with damp, mould, moss and frost being serious issues. The only way I'd countenance it is if using non-slip inserts......and they can lead to water pooling and the early rotting of the timber.

 

[MikeG.]

Your design is a little too steep. With a 700 (approx) rise and 760 total going, your angle is 42.6 degrees. 42 is the maximum indoors (there are no regulations outdoors), but I suggest that for someone with a new hip, you should be making it the easiest stair you can. I'd certainly be making that out of brick and paving stones, personally, and much shallower.

 

[Mike Jordan]

I would agree with making them easygoing. The best method of making timber non slip is to fasten chicken wire to the walking surface of the treads.
This method is much used at marinas to make the jetties safe for use in the winter.

 

[AJB Temple]

I would not countenance doing this in wood. This is a morning's job at most, in brick with paving slab tops. Based on the look of it, probably two steps, keep them wide and deep (I would probably make each step the depth of a 30 cm slab. Safer and better and will look better as well.

 

[AJB Temple]

by "depth" I mean the tread depth, not the height.

 

[dzj]

I remember a formula, 2H+B=63cm from when I was in school (Cambrian period ), where H is the rise and B is tread. It might be of use to determine the size of steps.

 

[Inspector]

Here are a couple stair calculators that may help. The first is in Imperial only and the second site, an Aussie one, has both metric and imperial.

https://www.mycarpentry.com/stair-calculator.html

https://www.blocklayer.com/stairs/stairs-toplevel.aspx

Pete

PS. Don't forget to make the handrail, even if it is only a few steps high. I would also make a landing at the top of the stairs to get sorted out before descending. You might want to consider down two steps to a mid landing and then put a quarter turn and another couple steps down to the lower pavement level.

 

[thetyreman]

thanks for all the replies, very helpful.

I might make a WIP about it, but only if others would find it useful.

would you let the wood acclimatise outside? I'm thinking of doing that for a week in stick with an anvil and under a tarp before starting working on it.

 

[MikeG.]

........would you let the wood acclimatise outside?........

You're still planning on making it from wood?! I'd say that was most unwise. Even if it is a temporary get-out-of-gaol thing, they have a habit of becoming permanent. I'd strongly advise having a rethink about this idea.

 

[Harbo]

I’m amazed that anybody can get out safely from that doorway, how did the builder get away with it?

Rod

 

[thetyreman]

I’m amazed that anybody can get out safely from that doorway, how did the builder get away with it?

Rod

that was the cowboy that built the conservatory, I could go into a massive rant about him, by the time he'd finished my parents wanted nothing to do with him, so it's just been left for years like this, not brilliant I know but it's about time something was done to solve the problem.

 

[AndyT]

I don't disagree with the advice about wood and temporary arrangements becoming permanent.

But if you want a quick fix, my neighbour had a similar problem while remodelling his patio into a deck. Having removed the 'temporary' stack of concrete blocks he made a wooden stair like you need.

He saved a lot of work by using a closed string design, rather than a cut string like you have drawn. Timber was probably about 9" x 2". Two sloping sides (strings) with bevel cuts at the ends (one vertical to touch the wall, the other horizontal to rest on the ground). Three treads, held on large lag screws driven through the sides into the ends of the treads. No risers. Not fine construction but sturdy enough to last a year or so while he got the proper job done. Time taken was only an hour or two with a chop saw.
He supported the wall end using a couple of joist hangers.

I should also add that non-slip tape is good and easily available at Toolstation. If you need something more durable, offcuts of heavy duty roofing felt can be glued or screwed down.