Minimum tile spacer for ceramic floor tile

[Possom]

If using T-shaped tile spacers with ceramic floor tiles which measure 20.5 x 61.5cm and which are placed on a marine plywood floor, what would be the minimum spacer which could be used?

The tiles are timber effect tiles, so the preference would be to have the minimum amount of grout visible.

I'm sure 3mm could be used, but what about 2mm?

Thanks.

 

[chappers]

either