Hi all,

I'm planning to tile my own bathrooms. The one from the groundfloor has a concrete subfloor, the ones from the upper floor has a 22mm chipboard tongue and groove. The largest bathroom is about 2x3m.
From what I read about this subject on the forum a solution will be 6mm hardibacker (with a 7mm porcelain tile will be same level with the rest of the floor in the house).
Will this be ok, or I need to go with the 12mm plywood?

Thanks,
Christian

You will need to check if there is any deflection in the floor first before making a decision. If the floor is solid, then yes Hardiebacker 250 will be fine.

How should I check for deflection?
Should I understand that the 12mm plywood will be the best approach? There is anything else around 6mm that will do the job?