Possible Leak In Pool?

I own a home with inground pool in Vegas....pool was probably built around 1970...I presume it's a traditional gunite/plaster type of pool (it's not a vinyl liner, looks all original).

Had the pool inspected as part of the home purchase in 2010. Other than some falling tiles and a bit of "heaved" up area on the surrounding deck caused by a small fir tree (landscaped around the deck), everything seemed to be in okay condition.

Swam in the pool last year, noticed no problems. To my shock upon getting into the pool for the first time this year, I noted several areas in the shallow end where the bottom of the pool in certain spots was squishy or bobbing up. I reached down and pressed with my hand and indeed, these particular areas were very squishy and floaty, almost the way a liner would be. But this is concrete/gunite ...never had an experience like this (owned a pool years ago that was a new pool), so I'm naturally very concerned. So, I'm trying to figure out what the heck is going on with this, if there's a leak that has somehow gotten under the plastic and affected the gunite/concrete beneath. I haven't had a pool company out to look at it yet as I'd like to have some unbiased info here first. I take care of the pool myself, clean it with a typical pool vac.

Question: could the suction of a pool vac have dislodged the contact between plaster and gunite and allowed water to bubble in there and cause this floaty/ squishy phenomenon in these selected areas? So far, I haven't been able to visually detect a crack, so it may be something subtle going on. It really freaked me out, to say the least. Could tree roots (small but enough to have caused some heave in the patio), created this problem? I have somewhat felt I'm having to add more water than usual to keep the water level up, but this is a very hot climate out here so it could be a normal amount.

Should I do a leak test? and if so, what type and how? The only other thing that I did to the pool was to drain the attached spa so I could retile some areas around it so it wouldn't get wet. I left the spa empty for about 7-8 days back in May and refilled it. I wouldn't think that would have made a big difference to anything. To make clear, the pool isn't "floating" or some such thing. It's these isolated areas on the bottom of the shallow end. I have no idea if there's anything going on in the deep end, I can't dive down to investigate the pool floor down there. Thanks so much for any info or advice!

Let's start with the bucket test to see if you have a leak. If you go to the subforum called "Inground Pool Construction and Repair," you'll find a stickied thread (4th thread from the top) about how to do the bucket test. Report back with what you find out. I'm also going to ask PoolDoc to look at your thread as I don't know much about these plaster/gunite pool finishes.

Welcome to the Pool Forum!

thanks so much, I will do a bucket test in the next 1-2 days and let you know how it goes. Thanks for referring my post to PoolDoc also. I would be curious if anyone else has experienced "floaty" areas on the bottom of their pools. As far as I know this is a regular plaster pool (no liner), I had no idea that solid plaster could "bob up" the way these areas are, to the point I can push down with my hand and feel the "give". Maybe there is some flexibility of this material, even though normally it has a hard concrete feel to it. The first two pool steps going into the shallow end appear solid without any bobbing or floaty/squishy feel....once past the last step and down one the shallow floor is where these particular areas are found. I'm mystified! Thanks again! (btw, i made a typo in my earlier post - plastic, I meant to type plaster. There is no plastic or other vinyl material. It's ust a traditional plaster pool.

Hi Butterfly;

It just sounds like you've got some patches where the plaster is delaminating (coming unstuck) from the gunite. This can happen if you leave a pool dry and it gets very hot; it can also happen if it freezes while dry . . . and it can happen for reasons I don't know, too.

If that's what it is, the only fix is to drain the pool. chip out the popped plaster, and replace it. But, I do NOT recommend that. Often when you do this you'll find that the area NEXT to the pop is also delamininated, and that if you REALLY want to solve the problem, you'd remove ALL the plaster, and then re-plaster.

If I were you, I'd avoid standing on those areas, and just leave them alone till the pop free. Then, drain and patch just THOSE areas, till you are ready to do a complete re-plaster. I've seen pools go a LONG time with a few popped areas.

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Originally Posted by PoolDoc

Hi Butterfly;

It just sounds like you've got some patches where the plaster is delaminating (coming unstuck) from the gunite. This can happen if you leave a pool dry and it gets very hot; it can also happen if it freezes while dry . . . and it can happen for reasons I don't know, too.

If that's what it is, the only fix is to drain the pool. chip out the popped plaster, and replace it. But, I do NOT recommend that. Often when you do this you'll find that the area NEXT to the pop is also delamininated, and that if you REALLY want to solve the problem, you'd remove ALL the plaster, and then re-plaster.

If I were you, I'd avoid standing on those areas, and just leave them alone till the pop free. Then, drain and patch just THOSE areas, till you are ready to do a complete re-plaster. I've seen pools go a LONG time with a few popped areas.

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Thanks so much PoolDoc for your reply!

It helps a lot to understand the situation for sure! I bought the house/pool in 2010 and don't know if the pool itself has ever been drained and left to dry in the hot sun, so I don't know the history of what may have been done to this pool in the past. But as you say, de-lamination could happen for any number of reasons. I had wondered if the vacuum/suction of the pool vac could dislodge it with strong suction. Whatever the case, it sounds like plaster delaminating from gunite is most likely what is happening.

The bucket test I did is inconclusive. It appeared to be approximately the same amount of water had evaporated from the bucket as from the pool - a bit more than an inch over two days or so in very hot weather (105-107 degrees in Las Vegas). So, it didn't appear that there's a noticeable leak going on. Hopefully that's good news.

Yesterday I got into the pool and walked around and observed more and found several more "floaty" areas on the steps which are difficult to avoid stepping on while getting into the pool. But I will certainly do my best to not put pressure on them unnecessarily. I agree, it's probably best not to do a complete drain and get into a big problem of having to do a complete replaster. I don't have the $$ at this point to do it and if it's true that the pool can go a long time with these few popped areas, I would opt for that until I see otherwise. I have never been in a pool with a problem like this, so it's all new to me.

I guess my main concern is that if I don't address the issue now, am I looking at severe damage to the pool, or is putting it off a viable option? I don't want to end up with more problems down the road than I have now. I also am concerned with my pool vac suction being so strong that when I vac over those areas, it pulls it even more and causes more delamination. But I really have no chocie but to vac, as that's the way I clean the pool, although I often try to keep cleaning and vaccing to a minimum during winter months when pool is not in use. Thanks again for your helpful info, greatly appreciated!

If anyone else on the forum reading this has experienced delaminated areas, feel free to post about your experiences. I had no idea such a thing could happen in a pool whatsoever!

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Originally Posted by butterflyblue

The bucket test I did is inconclusive. It appeared to be approximately the same amount of water had evaporated from the bucket as from the pool - a bit more than an inch over two days or so in very hot weather (105-107 degrees in Las Vegas). So, it didn't appear that there's a noticeable leak going on. Hopefully that's good news.

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It's good news.

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I don't have the $$ at this point to do it and if it's true that the pool can go a long time with these few popped areas, I would opt for that until I see otherwise.

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No guarantees, but I've seen pools go years with popped plaster. In some cases, I had to drain them partially, remove the pop and flakes (where it had broken) and patch them, which is a job you CAN do yourself, if you are sorta handy.

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I guess my main concern is that if I don't address the issue now, am I looking at severe damage to the pool, or is putting it off a viable option?

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I'm not aware of any severe damage that would result from postponing repairs. You are probably looking at a full replaster, regardless. And leaving the pops in place isn't likely to cause other areas to pop.

Ben

thanks PoolDoc for the further info.

At this point, I will have to assume that delamination is indeed the problem (fingers crossed it's not something more serious). I guess the most amazing thing about this is that i had no idea that solid plaster could develop these types of floaty areas, almost bubble-like or squishy areas. In my mind, plaster is like concrete, but obviously it can "move" in a sense, or has some type of flexibility once water has encroached and there's been a separation between plaster and gunite. As far as patching it goes, I have heard that some patching can be done underwater without draining so that's probably what I would go for (least expensive option when finally necessary), mainly because homes out here aren't worth the money to pump a lot of $$ into them due to the housing crisis. At sale, I'd never get my money back out of it, so everyone in Vegas tends to approach repairs this way unfortunately.

Anyway, THANK YOU so much, your help is truly appreciated and I will be sure to visit pool forum for my future pool advice and needs.

Solid plaster is a 3/8" - 3/4" thick layer of marble dust + white cement ON TOP of 4" - 8" thick gunite or shotcrete. Delamination occurs when the plaster layer detaches from the underlying gunite.