I'm converting a bedroom into a bathroom. It looks like the current subfloor is 1/2" MDF or Particle board (I'm not really sure). This sits on top of 2x8 tongue and groove.
I've read that MDF and Particle Board both are not ideal for bathrooms because of how they retain moisture. We plan on using ceramic tile throughout the whole bathroom so I was wondering if I should replace the subfloor with something else like plywood or if I can just use some sort of underlayment. If I use an underlayment, what should I use?
Here's a close-up of the subfloor: