Wanting to get best prep on a block and beam floor fibre reinforced screed. I have tiled outside before matting etc was ever used. What I normally do is prime, anti fracture tile? On balconys where there is bitumen I would use the floating system (cant think of the name) water runs out from beneath Lol. Senile I think ? Ready for abuse, but think this should be explained properly to all as a lot of floors are continuing outside. Did a pool surround 12 years ago direct onto concrete still fine, just needed a clean.