Heck of a gap you got over there mate. I always try my best to straighten up the walls prior to waterproofing/tiling, that saves me adhesive and installation time. Easier when installing the tile as well.
Is it a shower? If yes, you got to do some waterproofing over there.
There's a lot of material available online regarding ancient waterproofing techniques. A good start would be to Google the term Opus Signinum aka Cocciopesto technique.
There are other waterproofing Methodes used throughout the history from clay, natural resin and fats, soap-oil mix to volcano...
It is done with tile adhesive to create a nice smoot pitched down transition between the floor tile and mosaic. It is doable. Send us more pictures before and after. Good luck!
Floor needs to be dry 100% then Ditra Matting installation and of course tape the joints. That's the best you can do as a tiler. Send us some pictures. Good luck!
That gap is way too much for a shower. If the shower tray is solid, you can remove the last row cuts and redo them to eliminate the huge gap. You can silicone after the tiles are redone. That would be the best for that shower. I would waterproof the area as much as possible. Send us some more...
Install anti crack membrane Ditra matting, any brand would do.
https://www.tilingsuppliesdirect.co.uk/product-category/wetroom-systems/decoupling-membranes
Schluter Kerdi 200 like products are perfect for the application as long the wall is perfectly sound, make sure you apply the corner band up the wall/corner. Send us some pictures. Good luck!
It looks like that floor was designed for vinyl flooring. The green tile is vinyl. Get a dehumidifier to dry up the soil then you can proceed with the concrete and tile. Ardex products are good. As far as the bitumen blackjack goes, make sure Ardex NA is compatible with bitumen. Send some...
Water Damaged Shower Repairs
Shower tile repair – water damage – tile waterproofing
Do you have shower leakage that goes downstairs leading to either your main floor or basement? Read this blog to find out why the worn-out shower leaks downstairs. You are not alone, in fact, water damaged...