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 ,

[garythetiler]

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

[garythetiler]

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.

[whitebeam]

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.

[JLM Tiling]

Well rough Jay! And whoever did the vandex didn't seem to care much either, snots all over the place and brushmarks and all sorts. Would rather have had the bare steps to work with. Just glad it's day work!

[Phil Hobson]

Gary I could not fault your reply, that is exactly the way I was taught at college, absolutely spot on my hat goes off to you. This is why this forum is the best.

[jay]

Well rough Jay! And whoever did the vandex didn't seem to care much either, snots all over the place and brushmarks and all sorts. Would rather have had the bare steps to work with. Just glad it's day work!

same thing happens over here people don't care anymore as long as there work is done stuff the next person

[JLM Tiling]

I can mange the maths no problem but thanks all the same tony. The problem is not being able to take a step down any. So would have to work off the largest step. Or I could just use SLC on the largest step and keep it down to only a few mm depending on how rough the vandex is on that particular one. Just want everything spot on before I even get the tiles out!

[Tony73]

are them steps outside or in?

[JLM Tiling]

outside

[Tony73]

well, good luck anyway

[garythetiler]

I can mange the maths no problem but thanks all the same tony. The problem is not being able to take a step down any. So would have to work off the largest step. Or I could just use SLC on the largest step and keep it down to only a few mm depending on how rough the vandex is on that particular one. Just want everything spot on before I even get the tiles out!

what floor finish is at the top of the staircase?

[garythetiler]

here are some pictures of the work i am doing at the moment some of the concrete is up to 15mm different fro step to step with the raked riser you talked about using the maths I have managed to make all the steps equal and made stair strings fro the tiles too all in 4.8mm porcelain

[JLM Tiling]

Its still the vandex. The steps go up on the side of the building to a top flat area about a m2 or so and the door is on the left. Tiling that as well. I'm wondering now how much height I have at the top that I can eat into. Also the top step is the highest so I could just use 6mm board on the top and thats one less to worry about. I think I'm going to follow your advice Gary on working out an average etc. The whole thing is tricky though, if it wasn't for the substantial curve on the internal angle and it was all just nice and square then I could just cut a load of boards to the established average and just bang them in but I cant do that as every curve is different! And it also means I havent got anything to measure from to be spot on to the mm. The whole job is just bloody frustratingly awkward!! Pulling my hair out all afternoon!!

[JLM Tiling]

Yeah that sounds like an identical situation! How did you do it? I can do the maths part easy to work out what each one SHOULD be but how do I get it there?!

[garythetiler]

there are several ways of doing it the top rise height being larger isnt a major issue ,what type of tile will you be using on the stairs

[JLM Tiling]

Porcs, not sure how thick

[JLM Tiling]

The top one is 179mm, the rest are around about the 174mm mark with the very bottom being 160mm. What is the tolerance according to BS do you know? Cheers for all your help with this one Gary it is starting to click me thinks!

[garythetiler]

Porcs, not sure how thick

what size 60x60?

[JLM Tiling]

I think they're 600x600. Bigger than the steps, thats all i need to know! And the customer wants to have one full tile centre and then a cut either side of it just to make it even more complicated!! Loving it

[Tony73]

if its outside, than you do 2-4mm fall for water to run off. so you can win some mm. on than and some on risers. As Gary said , work on average. I know stairs sometimes hard, when they are diferent sizes and not paralel etc.

[garythetiler]

[QUOTE=JLM Tiling;571088]The top one is 179mm, the rest are around about the 174mm mark with the very bottom being 160mm. What is the tolerance according to BS do you know? Cheers for all your help with this one Gary it is starting to click me thinks![/QUOTE you will need to do this in sand and cement for the treads and you may be able to stick the riser with adhesive but i am thinking mortar bed for the risers too
I would cut a gauging template and start from the bottom ,which i know is counter intuative but works for me when tilng stairs that are badly out, the guaging template is cut to the height of 2 step heights and the depth of one step cut away to form right angle which you can use to set each riser at exactly the same height and spacing away from one another once the riser are set you can back fill these with sand and cement and slurry the treads on here as picture of one i did like this a few years ago

[JLM Tiling]

I like the gauge idea, very nice. Only problem is getting around the curve. I'll take a photo tomorrow so I can show you what I mean. I'm gonna have to come up and out by at least 10mm to get past that in itself. I'll do that first so I've got a square angle to work from and then do it the way you say. Props for the advice mucker, helped clear it all up in my noggin. I'll take pics tomorrow and show you how it comes together. Might even go for JOTM!