Tiling over plywood subfloor - advice needed

[john738]

Hi, DIY home owner here in need of advice. Following a waste pipe leak that's now been fixed, I'm renovating my kitchenette. To start with I wanted to remove the old laminate flooring and put tiles instead. I removed most of the laminate yesterday and found that the 18mm plywood (please can you confirm it is plywood from the pictures?) subfloor is quite damp especially in one spot (see pic), the upper surface is a bit creased and uneven and damp to the touch, but overall the subfloor feels sound and firm. It looks like just the upper layer is affected.

I'm hoping the damp may be due to the waste pipe leak and that it will get dry in a few days, although that spot is not immediately close to where the leak was (the waste pipe is roughly 1m away, see pic).

The original plan was to let the plywood dry from the leak near the waste pipe then put a Schluter DITRA membrane on top of the subfloor and then tile over it.

Underneath the laminate there was a very light film substrate that left the wood surface quite sticky once i removed it. Also, I couldn't get all of the film off, there are bits left here and there.

If it does get dry over the next few days, can I just sand the plywood down to remove the stickiness and film bits and to flatten the creased area, and get on with the job?

Thanks in advance.

 

[Slippery]

...An old thread now but here goes..

I think you would get away with scraping the top layer of plywood off as best you can then using a flexible adhesive and screws, fix down a cement or wedi board, don't trust that ply at all, it's not waterproof or even resistant