Do you tile butt up to bath or leave a gap?

[Michaelsf90]

When tiling around a bath do you tile right butt up on top of the bath or leave a tile spacer gap? Plumber has fitted bath and siliconed. The bath is bang on level. Do I sit a spacer and then tile or sit tile right on top of the bath?

 

[tell80]

Yes, use spacers to keep the bottom course off the bath rim - then silicone the gap.
Why, because baths and shower trays can move with weight and heat - even with tub ledgers.
The slight movement can open a tiny crack which will allow moisture to creep in.