We installed a new liner in our inground pool last year with no problems. The bottom of our pool is sand which we tried to trowel smooth as best we could. Walls are steel which we covered in foam due to rusting.
We are just getting ready to close our pool for the season and found a "crater" of about 6" in diameter behind the liner. It is located just below the wall at the area where the down slope starts. It appears like the sand has eroded away in this area. There is a gap behind the liner and we are worried that the gap will either increase or the liner will not be able to survive with no support behind it in this area. We are thinking of pulling the liner back just enough to direct sand (using a tube and funnel) to the crater/gap with someone in the pool to pack it in. We would drain the pool down to that location first. Has anyone else run into this problem? What did you do?
Any help or advice would be appreciated!!