Went to start a job this morning to tile an exterior pathway joining 2 properties with 30x45 porcs.
The old tiles were loose and I lifted a couple to see they had been stuck down with what looked like bitumen. No grout had ever been put in and they had been down 20 years.
Customer arranged to have the old tiles removed a couple of days ago and he said the concrete looked good so arrived there today to start work.
Here is the path
But the above isn't the concrete substrate I was hoping for:
Think it is a 1 inch layer of bitumen - I'm able to mark it with my thumbnail and scrape bits off so it is softer than asphalt which I believe I could tile straight to.
How would you guys go about it? I rang Mapei tech and they said if it's bitumen then it either needs to come up or sand and cement screed over it.
I'm confident I can get it up using an SDS Chisel but was worried about the level of the final tiling with the drain in pic 2.
Help!
The old tiles were loose and I lifted a couple to see they had been stuck down with what looked like bitumen. No grout had ever been put in and they had been down 20 years.
Customer arranged to have the old tiles removed a couple of days ago and he said the concrete looked good so arrived there today to start work.
Here is the path

But the above isn't the concrete substrate I was hoping for:


Think it is a 1 inch layer of bitumen - I'm able to mark it with my thumbnail and scrape bits off so it is softer than asphalt which I believe I could tile straight to.
How would you guys go about it? I rang Mapei tech and they said if it's bitumen then it either needs to come up or sand and cement screed over it.
I'm confident I can get it up using an SDS Chisel but was worried about the level of the final tiling with the drain in pic 2.
Help!