Need advice in mitigating damage from catastrophic winter water loss from doughboy AGP

oceans2000

Member
Oct 10, 2016
7
Omaha, Nebraska
So I need some advice. We have a 40'x20' doughboy agp, came with the house when we bought it 3 years ago, near Omaha Nebraska. Huge deck around it. It's an acreage, so water is our own well. Past two winters went fine, but this winter something went wrong, and the pool has been precipitously dropping the past week, as the weather has thawed. I think the culprit is probably the drain in the deep end - the pipe comes up from under the pool, to the pump equipment. In the past two years I pumped air in that pipe till it was coming out the drain at the bottom, closed the valve - trapping the air in theory - and that worked fine. But judging from the faint ripples coming up around that pipe, I think the valve must have leaked air, letting water up where it could freeze, busting the pipe, or something. Guess I should have piled hay or something around it, and wrapped it in heat tape, but that's in the past now. There's about 4 inches of water in the shallow end as I write this, and probably in the morning there will be none, aside from the slow melt of the 18+ inch thick slab of ice now sitting on the floor of the pool.

I come here asking for advice on how best to salvage the situation. Running our well overtime to keep water in it is not an option, it drops at about 1/4" an hour now I think, and it's not worth burning out our motor or damaging the well itself. In talking with local pool people I was told there is a chance that if the liner shrinks, it could damage the structure of the pool. I'd like to avoid that, at least. Is there a chance that lining the bottom edge of the liner where it meets the wall with sandbags might help keep the liner under control? If I leave the pool cover in place to keep the sun off the liner, might that help delay shrinkage? Would hanging sheets against the sides and spraying them with water once a day possibly help delay the drying out of the liner? Is it better to just cut loose the liner now and not risk the structural damage? Just trying to figure out how to make the best of a bad situation.
 

Bama Rambler

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TFP Expert
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Jun 22, 2009
23,640
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If you could access the drain, you could use a yoga mat or foam pad of some sort and cover the drain with it and lay a few sand bags around it and see if that stops the leaking. Provided the pool floor around the drain is not wrinkled, that should work to seal it off.
 

oceans2000

Member
Oct 10, 2016
7
Omaha, Nebraska
Well, the water appears to have stopped dropping now, at least fast. Seems to be right below the level of the shallow end floor. So still a good amount of water in the deeper end. I can't reach the drain or really anything inside right now due to all the ice still in there. And the water would be ice cold. I'm really right now mainly concerned about trying to keep the liner from being damaged by shrinkage or wind. When the ice melts, and depending on how well I can function in the water which will probably remain very cold for some time after that, my plan is to cover the bottom drain and abandon it. I got a pool robot just last year, and it does such a good job I barely ran the main pump. Basically just opening and closing, and it doesn't need the bottom drain to function anyway, I don't think. So if the problem is limited to the bottom drain pipe, and if I didn't get too bad of erosion, I'm hoping to seal off the drain entirely, and be back in business, if I'm lucky.

But in the meantime, I need to keep the liner from being damaged, and that's why I'm looking for advice from people who maybe have some first-hand knowledge about how best to preserve a liner in this situation, ideally. I don't really get how wind gets behind the liner on the walls, I would have expected the metal panels or whatever behind to be a continuous sheet. But it appears that it does. For now the ice is holding the floor liner down, but that won't last forever. And losing the liner is costly, but not to the point we couldn't recover. But if the wall structure were damaged, that may make repair too expensive. I've read on the internet and had people tell me the liner can damage the wall, but I don't understand why it would not prefer to pull up off the floor before it would collapse the wall. So that's another question - sandbag the liner at wall base, or no?

I'd also be interested to hear thoughts about how best to permanently cover a bottom drain. The liner is an overlap one, so I have a lot of loose material to cut a patch out of. But will a 1/2" sheet of polyiso be enough, or for that matter the drain grate itself, be enough to stand up to the pressure? I was thinking of placing a loose piece of vinly directly on the drain, then fill with sand around till level with the top of the drain, then a sheet of polyiso, and then a piece of liner over that, chemically bonded to the main liner. I just don't want the drain to collapse under all that water weight (it's about 6 feet deep where the drain is). So I'm wondering if I need to get a sheet of pvc or aluminum or something to go on top of the sand to spread the weight a bit, followed by polyiso and bonded liner patch?
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
41,524
Tallahassee, FL
The damage to the walls can come from the liner shrinking and pulling down on the walls causing them to pull inward. I am not sure if you can save the liner or not at this point. Your main worry is the walls. I would think about making some supports to go from one side of the wall to the other-PVC or wood depending on what you have on hand or can get your hands on.

-main drain closing off-I am going to reach out to someone for this one. I know what I THINK would work but am not sure so .... @Pool Clown @ajw22 any input on this?

Kim:kim:
 

oceans2000

Member
Oct 10, 2016
7
Omaha, Nebraska
Well, i finally got down in and looked and the liner tore in many places around the bottom edge where it meets the wall, either due to shrinkage, or because it was so old an brittle that the wind flapping the liner walls caused it to break (don't know how old the liner is, it was here when we bought the house 3 years ago). These holes could not have been the original cause I think, or it would have drained totally in an hour, there's so many. I guess now at least we can remove the bottom drain entirely, rather than just cover it. I appreciate the attempts to help.