Help prepping treads and risers on external steps

[JLM Tiling]

Okay I know its late but need some help getting my head around this one.

Got 15 steps to do for a builder I work for but when they stripped away the old mort they discovered that there was a gap between each step ( the internal angle between the bottom of the riser and the tread) Anyway the steps have been vandex'd and they put in a mortar fillet and filled the gap. But now that angle has quite a substantial curve on it and it means that I can now no longer get the tile all the way in there. To overcome this the architect has asked me to use a cement backer board (12.5mm marmox) I checked with marmox and they said its fit for purpose. So loads of messing around basically.

Then the customer tells me that they want everything millimetre perfect. Perfectly square, perfectly flat and perfect continuity with every tread and riser. Exactly the same. Everything. I measured the treads and risers and they are all over the shop. The shortest riser is 160mm and the biggest is 179mm. Also the treads are different ranging from 9 to 10 inches. Just how in moses name do I get everything right? I mean seriously. I'm assuming that I'll have to take the biggest step there is and pack everything out to that height and width. But god knows where I'll end up! Thing is though I cant take off from a step as that would mean removing the vandex. Anyway at this point I just went home, far too late in the day to start messing about without having time to think and consult you peeps. Can anyone shed any light on this predicament?!

 

[jay]

Personally i would render the steps first as there could be a heap of trouble trying to sort it any other way ,

 

[Spud]

I am doing stair cases at the moment and they are difficult to tile ,you need to get a datum line from the top tread and measure down to the bottom floor this is called the storey height divide this by the amount of treads and each step will be exactly the same height you next need to get a plumb line up from the face of the bottom riser allowing the thickness of the tile and measure across to the face of the top riser allowing the thickness of the tile and measure the distance divide this by the number of steps and you will get the tread width once you have these measurements you can draw this on to the wall to mark out the string of the stair case after that you will have to prep the risers by rendering them out in sand and cement or use mortar bed fixing to get them exact

 

[Spud]

I will post some pictures of what I am tiling, it may help

 

[jay]

I am doing stair cases at the moment and they are difficult to tile ,you need to get a datum line from the top tread and measure down to the bottom floor this is called the storey height divide this by the amount of treads and each step will be exactly the same height you next need to get a plumb line up from the face of the bottom riser allowing the thickness of the tile and measure across to the face of the top riser allowing the thickness of the tile and measure the distance divide this by the number of steps and you will get the tread width once you have these measurements you can draw this on to the wall to mark out the string of the stair case after that you will have to prep the risers by rendering them out in sand and cement or use mortar bed fixing to get them exact

Spot on advice

 

[JLM Tiling]

Good points guys but cant render them as the customer is raging about the fact that the whole job was supposed to be finished in JULY! Nobody is getting paid until this finishes and that includes a few subby mates of mine. Cant wait for the render to dry and dont trust any of the monkeys that pass for plasterers to get it right with rapid render.

As for the maths, yes, in theory. But that gives me an average step, which would be great except that would mean having to take height off from the bigger steps and that is not possible due to the waterproofing.

 

[White Room]

Treads and risers should all be the same size anyway, blind people tend to get a feel for the steps...

 

[jay]

They sound rough any chance of some pics might help (bloody builders)

not sure over there but there is (Aus standards) for tread widths and riser heights might be worth checking

 

[JLM Tiling]

Exactly right. Just saying that whoever built the steps in the first place didn't agree!

 

[Tony73]

Hi, i have done alot of entrances, making drawings etc. Its easy, simple maths, depends what time you have got on this. i understand existing steps are all different sizes, to make all eq. you need to do some maths. if you like, can help you on PM.