IG Floating Vinyl Liner

[Vinyl_Guy]

These are tricky with out actually seeing them first hand. Each one has its own solution.

When you say "sides" do you mean the vertical walls, or the sloped areas (angles) just under the walls?

Getting some form of a siphoning hose type pump behind the walls and getting it going can't do much harm. It's really only speeding up the natural process of what's going to happen anyway.

The less the "bottom" is exposed to being saturated the better. So there is some benefit to draining the water out more quickly. When I say "bottom" I mean what ever material you have that is applied to the surfaces (besides the walls). If it's a sand bottom you might have quite a bit of jostling around of the bottom resulting in in wrinkles, pits, bowls, and other such depressions. Even humps where the sand gathered. If it's some sort of a "hard" bottom, there's still a chance for it to become malformed in some way, but less of a chance.

Any damage done might be a forgone conclusion at this point though, and you just might not be able to see it due to the fact the liner hasn't laid back down yet.

Answers/Opinions:

1. Seen it happen many times. I've seen liners where the main drain wasn't even visible, because liner had billowed from water so severely. Like a button in big leather chair. They eventually settled back down. The age of the liner has a lot to do with it. A newer liner still has a lot of its original elasticity, older ones tend to just fail, or settle back down with wrinkles and voids (bowls, cups indentations).

2. Your not going to push the water out from underneath the liner unless it has some place to go of less resistance. Till then it's there till it recedes naturally, or via a pump. I wouldn't go "pushing" anything around. The liner is more vulnerable to being punctured, torn or ripped when it's in this state. When your vacuuming or brushing a liner under normal conditions 1000s of LBS/Square Inch are holding it in place. Not the case when your manhandling a "bubbled" liner. Think of a water balloon versus a tight surgical glove. Equally applied pressures to both result in totally different outcomes.

3. Is an option, but if you've never worked with a liner in distress you might not see the signs of something going wrong. Or what to do exactly when.

A couple of things to look our for:

As you siphon/drain/suck the water out from underneath the liner, the full pressure of the water (in the liner) will now be on top of what your using. Make sure it doesn't have any sharp edges, or actually become stuck with the force of the water. The water should begin to lay the liner back down in the deepest sections first, due to the greater pressure. As it does, pull what ever pump or hose your using up further where the liner is still loose and has water behind it. Leaving it in over night as you drain the water, could result in you not being able to pull it out from behind the liner. They get "stuck" for lack of a better word. Make sure what you use, is as uniform and as small as possible. For instance if you use a garden hose, cut any "coupling" or threaded attachment at he end, right off. You want smooth, rounded, and small as possible.

As it lays down you can work it some what. The deeper you are under the water, the less likely due to the pressures. Work it with your hands first and foremost. Do not attempt to move it with any mechanical device, like grabbing it with a pair of pliers even if the "jaws" are padded. Above the water line an old fashion plunger works well. Place it on the liner, eject all the air (plunge it), and drag the liner by pulling on it from as far down the base of the plunger handle as you can. You can "drag" a liner with this method. I forget if it works well under water or not, can't hurt to try though. But I don't think you can get as much "suction" when it's water your displacing in the plunger.

If the water has pushed up beyond the bottom of the walls your foam (if any), might get pushed out of place. This is something you want to keep an eye on too. Open up a section of the liner from the track, lean in where the water is "billowing" the wall section, and try and get the foam to lay down flat again with your hands. Unzip as little liner as possible at first. Just enough to get your arm and shoulder down behind the wall so you can feel around for the foam. Do this before you start "draining" any water. Or now if you just going to let it drain naturally, while your still able to move the foam. Zip the liner back in right away after your done, before the pressure of the water begins to pull the liner down and away from the track. Don't leave it like that over night.

Don't drain any water out of the pool as of yet. The pressure of the water on top of the liner is keeping the pressure of the water below at bay. The less weight on top, the more it will push from below.

What would you say is the size of the worst area? A normal bedroom pillow? A medicine ball? Or bigger?

I've seen my fair share of water damage and you'd actually be pretty surprised how well vinyl liners come out in the end. You may have some wrinkling. There might be no way around it. It could be worse, I've seen them get lifted right up and out of the track for lengths up to 10 feet.

Good Luck.

[Poconos]

I have absolutely no experience with floating liners (lucky) but simple physics says if you keep a positive pressure the liner should not float. I'd first try and fill the pool as high as possible, to almost overflowing, and this should make the pool water level at least a few inches higher than the surrounding water level. Even this slight pressure differential should slowly force water out from behind the liner. Water got behind the liner some way and it should be able to be pushed out the same way unless the shell is so tightly sealed this can't happen. I have a high ground water level especially in Spring with the snow melt and keep the pool level higher than normal and have never had a problem. I suppose you could have high pressure spots depending on underground flow paths and surrounding terrain and if this caused the problem just ignore what I said.
Al

[Tillysaint]

Thanks for the advice.

I did let the pool heal itself. In some places I helped (nursed) it along with a squeegee. It took several hours but I have no creases.

The pool installer told me there shouldn't be a problem with my pool if I removed some of the liner & inserted a cut-off hose into it to pump water. Although I trust this guy (has installed many pools over the last 20 years), I didn’t need to do it. He was going to come to my house if the pool ’t heal itself.

Here is some additional information about my pool. My pool is a diving one, 8.5 feet deep, 16 X36 feet rectangle, & installed in 1990. It has vertical walls on all sides including sloped areas in the deep end. The walls are steel and the sloped areas & bottom were done with pool cement. There’s only foam under the steps in the shallow part of the pool. I was there when the pool was installed. They had to “carve” sections of the bottom of the pool into bed rock.

Two years ago I replaced my original liner (good shape but bleached) with one that is a little thicker. When they removed the original liner, we all were surprised how well the pool looked underneath! No repairs were needed. The person who originally installed the pool also did the new liner and advised me with this problem.

The vinyl liner had lifted in spots in every section (floor & sides). The worst area was the slopping side under the dividing board, a section about 12 feet long 2 feet wide. I would’ve probably attacked this side first with the pump but it corrected itself. The other sections varied but much smaller than the one under the dividing board.

Based upon previous advice I received from the installer, I only let the pool fill up to & near the liner track & then dump the water. He told me that water can get behind the liner if you let it overflow.

I normally don’t have problems with the liner lifting since I believe the drainage is pretty good. Who knows what happens with the water table but we’ve been in a drought for the last 3 years. My pool guy told me that the new liners, although you can get them thicker, are not as good as the old ones since they’re made with a different formula.

We’re currently waiting for Hanna. Is there a way I can prevent the liner from lifting with this one? Thanks

[Vinyl_Guy]

We’re currently waiting for Hanna. Is there a way I can prevent the liner from lifting with this one? Thanks

Well that wasn't too bad, and it sounds like you have a good tech to work with.

You could as soon as you see any "bloating" install pumps as you described. But use a discharge hose that's long and towards the natural drainage of the property. Otherwise sometimes the water just finds it's way back to where it was pumped from.

[Tillysaint]

I had a few notes & discussions about water getting behind the liner if you let the pool overflow past the track where the liner is attached to the pool.

Apparently some people are under the impression that you could let a pool overflow since the more water in the pool the less likely the liner will float. I was told not to let the pool overflow.

Any comments?

Perhaps there's not a definitive answer to this question since all the people I've talked to haven't had a situation where they had to let a liner pool overflow. With all the tropical depressions & hurricanes around lately, it's been possible to get 6-8" of rain overnight. Of course, with a power failure you might not have a choice since you can't dump water out of the pool.

[Vinyl_Guy]

I don't think it's ever good to let the water over flow in an IG vinyl.

Some coping and accompanying deck systems are nearly watertight, some are not. Even if it is water tight, if you've got a small apron of deck around the pool of about 4 feet, the water overflowing out of the pool might just find it's way behind the walls, and eventually under the liner. So you could be shedding the volume of water that falls onto the pool behind the walls and eventually under the liner.

If water gets behind a liner, the most water in the pool is usually best because it prevents the bloating behind the liner to increase to its maximum. Draining a pool for instance to relieve the pressure on the wall (form the water in the pool), to insert a siphoning hose behind the liner, might actually cause more harm then good.

Think of the weight of the water in the pool, it's enormous. Then think of how much pressure is being exerted to push that weight upward. Any less weight on top of the liner only increases the chances of the liner becoming even more displaced.

Ideally you'd want the most water in the pool possible with out overflowing. Not an easy task when you'll be getting 6-8 inches of rain fall. If you going to drain the excess water out of the pool, discharge it to a location that's well away from the pool. At least then the water getting behind the liner is only the water falling where you can't control it. Namely on the deck and the surrounding ground. If the rain fall exceeds what those areas can safely drain away from the the pools in ground profile, there's not really a lot you can do about it. You just don't want to add to that by discharging water that fell in the area of the pools dimensions. When a pool overflows it's the same as the roof on you house. Your adding a volume of water from a larger area, to a much smaller one. You don't want to do that especially when the smaller area is already saturated.

It's a tough balancing act. When installing pools with a ground water problem, I've had to go sometimes 100's of feet with the discharge before it wasn't just cycling back into the pumps at the bottom of the pool.

There is of course the option (sometimes a must with gunite or solid bodied pools) of installing a Hydrostatic Relief Valve in a main drain. A Hydrostatic Relief Valve is a simple device. It's an opening to the area below the liner in the form of a threaded fitting in your main drain. On top of the fitting is a cap with an o-ring that seals it, and a spring to pull the cap down tight and keep it in place. Between the spring and the water in the pool the cap stays water tight. But, if the water pressure coming form the bottom of the pool exceeds the the pressure of the water in the pool, the cap lifts up and releases water into the pool from below the liner.

Hydrostatic Relief Valve

Although installing one post construction without the the proper preparation greatly reduces their effectiveness. Ideally if a water "problem" may be persistent in an in ground vinyl liner pool, stone can be placed to direct underground water towards the Hydrostatic Relief Valve. That stone has to be placed during the construction, and before any hard bottom is troweled.

They're often installed in gunite pools if there's any chance of a ground water problem. If not a gunite can pop itself clear out of the ground by several inches snapping any fittings directly hard piped into the body. I've seen this happen, it's not a pretty sight and a huge repair cost, sometimes costing more then a new pool since the old shell has to be extracted most of the time.

[Tillysaint]

Thanks for the responses.

I understand to not let a pool overflow. However, there are a couple of inches above the liner attachment track before the pool overflows.

If you let the pool fill above the track but not overflow, is there a problem of water getting behind the liner through the track and causing the liner to float negating the advantage of having the extra water in the pool? In other words, do not let the water get above the track?

In my pool I would gain about 2 inches of area above the track while I have about 6.5 inches from the middle of the skimmer to track. In my latest situation the water was maybe a .25 inch below the track after the rain!