Renovating concrete and slate staircase

[gjores]

Hello friends, hope everyone is doing well during vacation time. We are going to (in addition to all other unfinished projects) renovate the slate stairs where plants have started growing.

Have questions:

1. The slate tiles on the steps are lying on sand. Is that a good thing? Plants grow like crazy there.

2. How do you fasten slate on the risers? Pl600? Some kind of magical adhesive?

Hope someone can answer and have a great time!

 

[Odi et Amo]

Are they lying loosely on a layer of sand?

 

[Njingan]

I attached slate tiles as a finishing layer on a retaining wall using stone adhesive from byggmax, I think the brand was bostik.
It's held up for over 1 year now at least.
Otherwise, you can surely mix some concrete and put it in between.

 

[gjores]

Are they lying loosely on a layer of sand?

Yep, they're lying completely loose on sand.

 

[Stefan N]

Isn't it leached concrete? The stairs aren't made of sand; otherwise, nothing would remain.

 

[gjores]

Isn't it eroded concrete? The staircase isn't made of sand, otherwise nothing would have remained.

No, it's a layer of sand on the concrete. The concrete is "pretty" fresh.

 

[Carl Johansson]

It's probably just a matter of mixing some mortar and re-laying the slate. If, for example, you're going to cast a new top, it might be a good idea to cast it on top of a layer of sand or another membrane that allows movement, but I can't answer why the slate hasn't been fixed.

 

[Odi et Amo]

Mortar or tile adhesive for natural stone and outdoor