I think that the main concern when drilling tiles is the water mess that might get onto fresh grout. So as advised above probably not good to drill when
tiles just grouted. But as soon as the grout goes off then away you go.
Our diamond cores work more like a grinder than a drill so you dont actually disturb the tile too much.
Done this way you can pretty much drill it while the addy is soft if you have to. But we dont recommend you make a thing of it.
In this article the basin is being fitted to the wall and the tiles had gone on that day.
I would suggest (for other readers) that if you are going to drill holes in tiles then
try to do it BEFORE you have grouted. This will remove the doubt that water coolant
will wash away soft grout if done too close together.
All the donkey work has been done on this job ahead of the grouting.
I think because it was an article photoshoot [ie not a real bathroom!!] then the
basin was fully fitted well before the grouting was done. Not even sure the
guys at Professional Builder even bothered to grout up this demo.
But the point remains that you can pretty much drill as soon as you want
BUT give the addy some time to cure and do it if you can before grouting.
Tiles already grouted? Then wait until it wont absorb and murky water used
to cool the diamond core drills
This video shows how mucky tiles can get when drilling. Again tiles are ungrouted so not spoilt
[video=youtube;F2Hk1eO8rOM]http://www.youtube.com/watch?v=F2Hk1eO8rOM&feature=player_embedded[/video]