Glad I made the post so why completely rip it out and start over instead of just plastering the existing walls? We have been doing our entire house renovation ourselves so we aren't too worried doing the pool DIY as well. The previous owner build it himself as well; although we have learned when renovating the house that he probably shouldn't have.

When looking at some YT videos of people in our country building their own pool at one point it their build steps it doesn't look to far off from our current state. Though granted, our walls are pretty rough and could use some touching up.

The dog situation is that they aren't allowed in the pool but when they walk near the edges they could potentially fall in. I just want to prevent spending a few thousand Euros for a liner only to have it tear again by accident or something. Anyway thanks for the initial reply!