Try to make your outlet holes perfect enough for the outlet ears (tabs?) to rest on the tile...and get longer screws. If your ears fall into the hole (like when I do it), you also get plastic washers.

Spacers are easy to use. Just make sure you pull the outlets forward before you tile so you don't tile any in place.

This one the tile was cut close enough that the "ears" are sitting on top and there was no need for shims.

{{!gwi}}

This one needed shims - it's that light green plastic bit behind the screws.

{{!gwi}}

if the "ears" were removed, then you are stuck using shims.

Don't use shims or plastic washers. The idea is to contain any spark inside the box. Spacers could expose wall materials to potential sparks and cause a fire.

They make box extenders for this purpose. You can get extenders of varying thickness or use a sleeve that slips inside of the box. I prefer the fixed sizes as the device is more stable when installed this way. You might need longer screws to hold the outlet if you have a thick tile.

Wouldn't you just adjust the location of the outlet box on the stud, assuming you know the wall will be tiled? Pull it out 1/4'' or whatever.

You could adjust them by pulling them out but presumably, the drywall is already in place so box extenders will work. robj is correct that the box must be closed. Renovation boxes allow some adjustment as well but they are tricky to use. You should NOT just pull the receptacle forward in the box and leave a gap. The junction box is there for a reason. Box extenders are CHEAP and available at the big box stores.

Thanks! I think I've got it.....I'll repost if we have any questions.

last I heard ceramic tile was not a flamable substance.

Not as far as I know either, but the national electric code requires that boxes set in concrete, tile or other non-combustible material be set back no more than 1/4" from the surface. If set in wood or other combustible material, they must be flush.

While the risk of fire might be very low, it would really stink to have your house burn down for lack of a 59 cent part. It would be even worse if your insurance company declined to pay. It could be worse yet to advise a stranger on the internet to do something that could cause such a situation.