Hello all,
I'm looking to do a minor bathroom renovation, namely:

Replacing floor tiles, because current tiles are quite slippery.
Install ceiling ventilation fan (includes drilling hole in wall and window for ducting), because I saw mold growing a bit on ceiling.
New installation of plaster ceiling

Is there anything that I should look out for when want to do this? Like if the floor tiles is hacked, need to make sure what they apply so no water leakage later (don't want to create problem for downstairs neighbor).

I am still looking for a contractor that are willing to do this small job in Ampang, if you guys have any recommendation can give me contact.