We are installing new ceramic tile flooring in our bathroom. The sub floor is thin and I think we should have used something different. Anyway we are ready to grout but the subfloor in one area is bubbling up and I am not sure how to fix it. Do I have to start all over and buy all new tiles and subfloor or can I screw it down and reapply the tiles in the bubbled area?

Sorry, you need to start over, but this time ask questions and do it right. It may be possible to salvage some of the tiles, but maybe not? As cheap as ceramic tiles are these days you may want to scrap everything.

Once ready, you can start with a description of what you're doing, with what and a full description of the subfloor system and how it's built.

Jaz

What will happen if I screw down the floor and not start over?

That is impossible to answer, but chances are it won't be good.

First of all I don't know what your subfloor is, what underlayment is over the subfloor and what adhesive you're using. I'm thinking if the underlayment buckled, it must be wood of some type which is not good.

How about you xplain specifically what you've got, what you're using and any other info you'd like to offer. It's not as simple as you may think.

Jaz