Tips on tiling with slate tiles

[iradney]

So the BF and I are renovating the house we're staying in. We're planning on tiling the kitchen and bathrooms with slate tiles, but have no past experience in doing that - they're going up on concrete walls - any tips for noobs?

[Shannarah]

All I can remember, if it is the proper natural slate, it varies in thickness, so at the start the bloke I was working for had me sort the tiles by thickness groupings to keep the floor mostly even. Whether this applies as much to walls I guess it depends on the situation.
The last thing I can remember is that it needs to be sealed with a specialized varnish type clear sealer, and re sealed every year or couple