Pockets Under Pool Liner

by Sue
(Broomall, PA)

I had an above ground pool installed last year, its about 19x31, pretty sure that includes the deck around it. We didn't do landscaping last year but this year we had a retaining wall built around it, except for the larger deck side.

I actually have 2 questions for you. The other day I was walking in the pool and noticed pockets in all 4 corners of the pool floor. Not right in the corners, but maybe about 4 inches away from the corner. I do feel the liner but what damage can this cause and what can I do about it?

My other question is what do you recommend I do between the retaining wall and the pool wall? There is about a foot and a half between walls.

Thank you very much. This site is great!

Hi Sue

The pockets in the liner need to be watched closely. If they stay small no damage will be done to the liner but if they continue to grow they will need fixed. The pool would have to be drained, the liner pulled back and the holes repaired. When doing this type of repair always leave a little water in the bottom of the pool so the liner does not shrink, wrinkle or shift out of place.

My preference for landscaping around a pool is black plastic and decorative stone. Avoid any type of vegetation because you don't want roots to go into the pool. The plastic is helpful for weed control as the ground around a pool is often wet.

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Pockets in Above Ground Pool


My husband and I got a used pool from a neighbor. It cost us nothing except to take it down. We found an installer to put it up for us, not with any ease I might add. Anyway, our backyard was sloped and previously could be wet in one area.

The area our pool is on is at the bottom of the slope in the wet area. After the pool was installed we did not do the landscaping right away. The installers did a nice job of leveling the ground however the ground seemed to have gotten moist and soft under the liner.

When you walk in the pool there are pockets at the bottom, soft. My question is what can potentially happen as a result? How long will the pool last in this condition. I also noticed that vacuuming is difficult because of the pockets.


Your biggest problem is just going to be the vacuuming. You could try unhooking the hose from the vacuum head and using just the hose in those areas. You would have to be in the pool of course.

Dips and wet spots under an above ground pool liner could also be a sign of a leak. Check the dips very closely for any sign of a tear in the liner. Liners can be easily patched if you find one.

The liner can be pulled back and the holes filled in if they really get to be a problem. This page about Pool Out of Level goes through the process you would use.

If cleaning is the only problem you are having I would wait until a liner change is needed to do any repairs. You might also look into how you can drain the water around your pool instead of under it.

This might help with the cleaning. Battery Powered Pool Vacuum

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Bubble Under Pool Liner

by Jan Uglis
(Chesterfield, MI)

My pool is approximately 23 years old and the liner about 10 years old. I happened to notice a bulge about five feet long under the liner near my pool ladder. The bulge starts about 1/2 way down sort of in the middle of the wall. The section where the bulge is located is partly in the ground about three feet (pool is a 28 foot round, 4 1/2 feet deep, Esther Williams. I want to get in the pool and feel the area, but I have not had a chance because I just noticed it late today(08/26/2010)

The weather in Michigan at this time August 2010 has been chilly at night; therefore the water being a little on the colder side. Do you think this happened because of the weather or do you think my pool has outlived its time?

My pool store told me not to allow anyone in the pool....nice especially since I have a big end of the summer BBQ this Saturday.

Thank the good Lord that pool season is almost over.

Thank you and God Bless

Jan Uglis, Chesterfield, MI

Hi Jan

It is impossible to say whether or not it is something to worry about without taking a closer look at it. A bulge poking into the pool could be caused by a tree root growing in that area. A sink spot in the liner might be caused by the wall finally giving out in that area. Most of the time when the wall gives out the dirt behind it holds the liner in place pretty well, so it's real hard to say what's going on.

What you have to look for are sharp edges. If the wall gave out and the liner is resting on sharp rusted edges of sidewall then you should drain and repair as soon as possible. If there are no sharp edges or sharp points coming in contact with the liner it's probably OK to use the pool.

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Recent Pool Install Rocky Bottom and Sinkholes

by Joan

We had our 15' round above ground pool installed 6/12/2013. They leveled our yard and installed it on blocks since we had underground phone wires. They did use pool base instead of sand since they had to carry it through our basement to the yard.

This summer has been pretty rainy so we've only been in it about 8 times. We first noticed some pretty bad rocky spots on the bottom close the sides.

Tonight (7/13/2013) we noticed several spots on the bottom where there was no sand (like holes. One was about 3" square by an 1" deep and the other was a little larger. These were further from the sides.

Should we call the installer? Is this something serious?

If he needs to make a repair can it wait until we winterize in the fall?

Hi Joan

I would definitely call the installer and let him know what is going on. He may have some idea of how he would want to handle it.

It sounds like you could let it go until the end of the season. The pool would need to be drained before anything can be done and this is usually the best time.

You just need to be aware of these spots and not catch a toe on them, and be careful cleaning around them. As long as you can keep from damaging the liner you should be fine for a while.

Comments for Recent Pool Install Rocky Bottom and Sinkholes

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Dec 21, 2020
Fixing Sinkholes
by: Anonymous

So I am trying to fix the sink holes underneath our above ground pool. I know I will have to drain it and pull back the lining but what is the best way to fill those holes and make sure nothing get underneath the pool to create those holes again because we do get mice in the area a lot. Please any advice would be amazing. I was thinking of using concrete around the edges of the pool.

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