Sand, no concrete behind tile

[whauser]

So we're renting this house while trying to buy it at the end of the month, we just moved in. This is in south FL so there are no issues with freezing. This is my first experience with a pool - an in ground, free form pool. The guy selling the house tells me they just had the pool drained and a new diamond brite coating applied. This was previously foreclosed so the pool has probably been neglected.

The problem is some of the pool tiles have clearly been caulked and some are missing and had plaster and diamond brite applied where the tiles would've been. In short, the tiles are not in good shape. It seems like this would've been addressed or at least noticed when the new coating was applied. They told me they were "not aware of any pool leaks." Now when brushing the pool I see some tiles falling off and behind them there are some roots and what looks like white sand. The coping on top is brick and the mortar is missing from several of the bricks all around the pool. I lifted a couple bricks off where the tiles are most readily falling off and all I can see underneath is white sand, it looks like there is a concrete wall behind the plaster of the pool but above that it sure looks like the tiles are just pressed up against the sand/roots and above that is the brick coping. I will say that there is no evidence of horizontal cracking along the tiles which, I think, would indicate a broken beam... but then I'm not sure there's anything behind the tiles other than sand. I don't know where this mysterious beam would be.

Obviously I need to call in an expert but I'm wondering what the deal is with this pool so I can tell if the "expert" is trying to screw me. I think the coping needs redone (probably with pavers along with the rest of patio area which is now sealed pea gravel) and then something needs to be done with the tile at the waterline. I'm also wondering if the new diamond brite coating was done just to hide other structural problems with the pool. I don't even know what to look for. I want this pool fixed right but I want it done cheap - nothing fancy or extravagant.

I think the pool is original to the house and the house is about 44 years old. I can provide pictures if necessary. I poked around under neath the brick coping with a screw driver and it looks like just white sand until I get to the area where the plaster would be and then there's a concrete lip. I don't know if the pool is gunnite, fiberglass, poured concrete, or some other construction method.

Thanks for any help you can provide.

[Guest]

Upon further consideration, would it be possible for the concrete forming the bond beam to soften with prolonged exposure to water? I looked under some other loose bricks and the "sand" is fairly firm. I could probably penetrate it with the screw driver but I'm wondering if it is a concrete bond beam that has softened with extended water exposure. Otherwise this pool has no apparent bond beam - a construction method I haven't seen described anywhere.

What's going on with this pool?