O
Old Mod
A fully bedded tile with a 10mm serration will only give a 3mm bed, be sure you are troweling in the same direction creating parallel ribs in the adhesive, and be sure to go the same way on your tile as the substrate, not perpendicular, if you're only flat backing the tile then it's not a problem.
10mm trim for a 9mm tile is exceptionally tight.
Offer a tile up to it, you'll know if it's wrong, go with your instinct.
Ad be sure to leave a grout joint between trim and tile, you may find that allows you to stick with the 9mm which will be more discreet than 12mm.
And if you're putting a cut edge to the trim, rub down the leading edge a little, you'll get a cleaner transition.
Good luck.
10mm trim for a 9mm tile is exceptionally tight.
Offer a tile up to it, you'll know if it's wrong, go with your instinct.
Ad be sure to leave a grout joint between trim and tile, you may find that allows you to stick with the 9mm which will be more discreet than 12mm.
And if you're putting a cut edge to the trim, rub down the leading edge a little, you'll get a cleaner transition.
Good luck.
