Tile on spa wall HELP!!

Hello, and thank you for allowing me to post to your forum!!! I live in Southern Nevada, My pool is inground, plaster, freeform, with elevated spa. About a week ago 2 tiles feel off the spa wall directly below the spill over. upon inspection i found 5 more loose tiles and removed them. Behind the remaining tiles (they are 2x2 tiles) there is a gap of about 1/4 to 3/8 inch that was full of water, these tiles do not move or feel loose. These tiles have always sounded hollow when you rap on them. I currently have the spill over turned off as to not put more water behind the tiles. My question is, is it normal for this gap behind the tiles? Can i just reinstall the tiles that fell out, or do i need to remove and reinstall all the tiles with a gap behind them? The pool is about 12 years old.

Thanks in advance for your assistance!! Roger.

Hi, and welcome to the forum!

Unfortunately, traffic is very, very slow this time of year, and there aren't many on this forum who have useable knowledge for your question. You can try logging out to the main Poolforum page and using the google search feature in any post by me, Watermom, or Pooldoc, but I would try www.poolspaforum, where there are many spa owners, and where you are more likely to find answers for this question.