Building hollow block wall on exterior tiled floor

[azk404]

Hi there,

 

I have a little DIY build coming up I need some advice on. I have an exterior garden wall that I would like to build with the same size and looks as the a current one but in another location. The new wall location is on tiled floor which I believe is already on concrete. Would I still need to cut away the tiled floor and make a new footing for the wall even if its already concrete below the tiles? Red circle is the old wall with blue square the new wall location.

 

New wall measures roughly 293x177

I was planning to use 440x215x215 hollow blocks for the base layer and then 440x215x140 for the wall. I will finish it with some pebble dashing and black paint to basically replicate what I already have in the photo below. 

Cheers
A

[azk404]

Bump :)