Help with plaster cracking and delaminating

[ShuaV]

Hi everyone, I have just been assigned to oversee the maintenance of a summer camp pool. I will preface my question by explaining that we don't have a pool company that can regularly service the pool, therefore most of the maintenance is done in house, and only occasionally when there is no other choice we bring in pros. Therefore much of the care given to this pool was probably incorrect. I'm trying to learn as much as I could to get it back into shape.

The immediate concern is that the finish of the pool is in bad shape. The pool seems to be made of concrete, than covered with a layer of plaster and then covered with blue pool paint. I'm told that for the last couple of years they have needed to repaint every single year because the paint and plaster was faded, and had cracks.

I took pictures but it seems I can't post them yet because I am new. Let's see if these links will work:





Any help and comments or tips much appreciated.

[PoolDoc]

Looks like you've got de-laminated plaster, that's been covered with multiple layers of rubber based paint.

If you are thinking that there's no good, easy, and cheap fix . . . you're probably right.

Your best bet is to
=> get some high-strength, low shrink patching cement (Thorite is a very high quality product of this type),
=> patch the holes
=> wait a month, and cover with more rubber based paint. (Paint doesn't adhere well to fresh concrete.)

Meanwhile, survey the pool, by tapping lightly with the round end of a machinist hammer. You'll be able to hear the other hollow spots. Plaster in good shape will 'ping', but as it delaminates you'll get an increasingly hollow 'pong'. (Really!)

Once you have the survey, step back and consider whether your facility is read to strip and replaster -- that's probably the least that will be required.

By the way, leaving a pool empty in freezing (or hot) weather will almost inevitably lead to this sort of damage.

Good luck.

[ShuaV]

Thank you so much for your detailed response!
I have a couple of questions:

First of all what is the underlying cause of the delamination? Is it just an issue of age made worse by leaving it empty through the winter? Or is it completly caused by the cold weather and it really would've just lasted indefinitely had been left full throughout the winter? Also is it possible that there is water seeping through the concrete wall from the ground causing or contributing to the delamination?

As far as repairing it, being that most of this work would have to be done in-house and we don't have any expert advising us on the ground, it would seem to make sense to me that the best option would be to stabilize the problem , and once we're sure that we're on the right track investing in a full repair. What do you think about this plan?

Just to clarify your actual repair recommendations, you are suggesting that I first fill in the holes with patching concrete and then repainting. Furthermore I should tap out the entire pool finding delaminated spots. Once I do that what should I do, should I break off all the delaminated plaster and then patch them and repaint them?

Also I would like to ask you, I'm not sure I understand why eventually all the plaster would have to be scraped. Is it because the delamination would just continue and continue and I'll just have to keep on repairing it?

I guess this comes back to my original question, what is causing the denomination.
Once again your advice is much appreciated!

[PoolDoc]

First of all what is the underlying cause of the delamination? Is it just an issue of age made worse by leaving it empty through the winter? Or is it completly caused by the cold weather and it really would've just lasted indefinitely had been left full throughout the winter? Also is it possible that there is water seeping through the concrete wall from the ground causing or contributing to the delamination?

Short answer: it doesn't matter; the same repair is required regardless. Slightly longer answer: leaving a plaster pool empty tends to result in delamination; I've speculated on plausible reasons, but I've never seen proof of a particular cause.

As far as repairing it, being that most of this work would have to be done in-house and we don't have any expert advising us on the ground, it would seem to make sense to me that the best option would be to stabilize the problem , and once we're sure that we're on the right track investing in a full repair.

Sounds like you're saying, "We need to find out how to do it right . . . and then do it that way", to which I can only say, "Of course!".

Just to clarify your actual repair recommendations, you are suggesting that I first fill in the holes with patching concrete and then repainting. Furthermore I should tap out the entire pool finding delaminated spots. Once I do that what should I do, should I break off all the delaminated plaster and then patch them and repaint them?

Unless you are ready to replaster, I would NOT recommend knocking out all the bad spots: once you do, patching may no longer be an option. What I am recommending is that you investigate the extent of the problem, so you can be better informed.

You've already told me that you don't have the budget to 'do it right', so I'm suggesting you take the time to inform yourselves as much as possible, so you can repair things the 'least bad way' possible.

Also I would like to ask you, I'm not sure I understand why eventually all the plaster would have to be scraped. Is it because the delamination would just continue and continue and I'll just have to keep on repairing it?

Properly installed plaster, kept submerged, doesn't delaminate. Whether 'doing right' requires just patching or a complete redo depends on what you find, when you check out the rest of the pool.