I have had a nightmare job I probably shouldn’t have took on. Called to a customers house and the previous bathroom installer has laid on a basic wooden frame. Mosaics on the bath panel and tiles along the top around the bathroom as a surround. 1 tile has broken and sunk slightly. It is also leaking.
I explained to the customer, that unless they wanted the entire bath ripping out and new frame fitting. That we could tank around the bath. Used Bostik shower adhesive and bostik grout, designed for swimming pools.
The edge of the bath was so out, I couldn’t lay the tiles flat properly even with packing the tiles out. It’s not my best work and I feel terrible as a result. They have used large format ceramics 60x30 to cover the old mosaics.
When I got advice from home (as you do) my dad said a more experienced tiler would never take on a repair job as you can’t really polish a t••d.
I've tried putting someone else's cock up right before and it's a nightmare! I wont even go near anything like that now, unless its agreed that a full rip out and re-fit happens. It's just not worth the hassle and it's also not proffesional, tiling onto something when you don't know what's underneath.
Tubbed adhesive is ok for metros on kitchen splashbacks and that's about it. Also, tiling over tile particularly on walls is a bad idea as most likely the substrate will not hold the weight of the tiles. Always best to strip things back in my opinion so you can see what's underneath and can try to ensure you are taking the correct approach.
I think the advice you've had already above is good. If you've only been going a few weeks (i've only been going a couple of years), I would suggest starting off with small, simple jobs, researching all you can and taking on more complex stuff as and when you feel you can. I did a couple of complicated jobs far too early on and the stress it caused just wasn't worth it! Be confident enough to say to the client that you need to go away and double check the best approach to their particular job as you want to make sure everything is perfect. Then come away, do your research and go back to them with a proper plan of action and an accurate quote. People will only see that as professional and you'll probably win more work, but also, you will be happy you are doing the right thing.