Sounds like somebody foisted a classic schlock job on you. My condolences. I had the same issue in my bathroom. Prior owner slapped up an illegal apartment, and put in a shower surround. He glued the surround right to the existing sheet rock. Horrifying.
Take the dry wall down, replace it with cement board. You can probably take down the existing surround, scrape it and clean it, and put it back up if you're real careful. I was successful at doing that.
Take a pic and post it. We can all weigh in on the correct steps to take.
Take the dry wall down, replace it with cement board. You can probably take down the existing surround, scrape it and clean it, and put it back up if you're real careful. I was successful at doing that.
Take a pic and post it. We can all weigh in on the correct steps to take.