Question for a tiler ...

[springmachine]

If anyone has any tiling knowledge or is a tiler please could you help?

I am needing to find a tiler for a kitchen wall that has previously been damp.

The damp has now been fixed but ever so often (because it's a humid room being a kitchen) the efflorescence comes through.

Is it ok to tile onto it as the wall is dry or could efflorescence affect it?

It can do but it's easy to fix, just rub down and seal the wall first. Traditionally this was done with a diluted PVA mix as a sealer and bonding agent but there are plenty of modern, synthetic products on the market. I would say just save yourself some money and pick up some Unibond or the likes.