Goldberg - i dont get what you quite mean about the backing,as surely there is nowhere the backing can go but behind the tiles.
I've seen tiling jobs where the trim was mistakenly left off and then fitted after the tile adhesive had gone off.
You can achieve this by cutting off the backing. Having done that the trim can be fitted either way around, although most trim is not symettrical in profile so one way will fit better than the other.
It's hard to tell from the images, but it looks suspiciously like that's what's happened.
The advice i would appreciate most is where we go on the extra £500 he is owed.
The principles are:
1. You must pay him all reasonable charges that he makes.
2. He must use reasonable skill and care in doing the job.
3. If there are snags, then you must tell him and give him the opportunity to remedy the problems, at his cost.
4. If he has damaged your goods, then he must compensate you either by replacing them or by reimbursing you to their value.
The rest has already been said - if he claims, in court, for what you owe him, then you can counterclaim for what he owes you.
What i feel like doing is docking his money to what we have to buy and paying another tiler.But i dont want to be in the wrong here.
But would you now trust the guy to put it right if it was your bathroom.[/quote]
I don't know your guy, and what your past relationship is, so I can't say whether or not I would trust him. I don't know why you trusted him before if you feel that he didn't deserve it.
There's no easy way out, but if there's a dispute in the making, then I would negotiate some compromise with the first contractor and then engage someone else to take ownership of the repairs, and pay them what they ask for.
If you find yourself out of pocket then it might be some comfort to you that £1500 was incredibly cheap, and that you've learned a valuable life lesson.