Bathroom sub floor damp

[Alan Diamond]

Hi All,

I just gutted a bathroom in my first duplex!  The floors were terrible, porcelain tile over cement board.  The cement board was the consistency of west sand, and after a layer of linoleum/tar paper, I got to the original hardwoods. The tub perimeter was quite damp at this level.. Do I need to remove that as well, or can I just let in dry and use self leveling cement on top? Plan is to use Schluter-Ditra as a strong barrier and basis for "normal" bath tile... Thoughts?

Thanks in advance

Alan