Wonky outdoor steps - is this impossible - Tile Advice

[AndyT]

Hi. Newbie needing advice from the experts.
I have outdoor steps which I would like to tile with R12 600x400 porcelain 10mm tiles. Problem is the steps are far from square and level - see pic.
There is a general slope, but the tiles rock significantly and the front faces are not straight. We get a lot of rain and frosts here in Aberdeen so I need 100% bonding.
Can I level this up with skim of adhesive first and let it dry.
On the nose of the steps, is it OK to set the tread tile back by 5 mm and fill the fillet with grout.

 

[Bond]

Not a job for a newbie lm afraid. Would take quite a bit of skill and know how to sort that lot out.

 

[AndyT]

Not a job for a newbie lm afraid. Would take quite a bit of skill and know how to sort that lot out.

Difficult, but I have to try and I have done some tiling. I was hoping that I could apply adhesive, pull that straight edge over it to level it up, let it stiffen a bit and then smooth it over, let it dry for a day - may take a few goes. What would be the problems - will adhesive stick. Then apply tiles with a 15mm notch.

 

[Steve6690]

Rather than trying to skim it all over with adhesive - which I think will be quite difficult to get right - I'd probably get some exterior rated tile backer board such as Marmox and use that to give you a nice flat surface. It should give you a bit of scope for adjustment too. Stick it down with a Pourable Thick Bed adhesive.
Then use the same adhesive for the tiles. You shouldn't get any voids with this method, which is how I'm doing my own garden steps.

 

[Bond]

Lots of ways to go about it, personally for that job I’d go for 20mm thick porcelain exterior paving. Start by getting the bottom riser true and level, level tread to that and tile tread, ditto, ditto, On the other steps.

 

[AndyT]

Rather than trying to skim it all over with adhesive - which I think will be quite difficult to get right - I'd probably get some exterior rated tile backer board such as Marmox and use that to give you a nice flat surface. It should give you a bit of scope for adjustment too. Stick it down with a Pourable Thick Bed adhesive.

Thanks Steve - Good idea, I will look at this, although I dont want to add much thickness at side of door. How do you use PTB - still with a notched trowel? To avoid a very sharp edge, is it OK to set tread tile 6mm back from riser and fill with grout, and/or just grind the edge of tile to a bevel.

 

[Steve6690]

I mixed it as per instructions and just poured it out where I need it, spreading it with a round notch trowel, but I make sure there aren't any voids. It's thin enough that when you bed the boards/tiles down it will squeeze out from underneath.
I'm not sure about the tread tile tbh. I think I'd go with a metal step trim. such as Schluter. I did read on here a suggestion of beveling or bullnosing the edge as long as the tile is full colour all the way through.