GJJ Posted July 26, 2009 Report Share Posted July 26, 2009 We just had our pool drained and hired a company to fix broken tile Friday and Saturday. Saturday at noon, we started refilling the pool. This morning (Sunday) we noticed the plaster is bubbling at the bottom of the pool. We live in Southern California and there is not a water table to worry about. Does anyone know why? Quote Link to comment Share on other sites More sharing options...
quantumchromodynamics Posted July 26, 2009 Report Share Posted July 26, 2009 The plaster is a mix of white cement and marble aggregate that is applied over the grey structural concrete shell. If the plaster temperature changes too much too fast it will expand or contract at a different rate than the underlying shell. This causes the plaster to become delaminated. The plaster becomes unbonded from the grey concrete. If the plaster was exposed to the direct sun, it probably got too hot. Before filling, the plaster should have been checked for delaminations. You can check by tapping on the plaster with the plastic end of a screwdriver. A delaminated spot will sound hollow and not solid. The delaminations have to be cut out and patched with plaster. If you're lucky, it will only be a few spots. In the worst case, you will have to have all of the plaster removed and replaced. Why did you completely drain the pool? Quote Link to comment Share on other sites More sharing options...
GJJ Posted July 26, 2009 Author Report Share Posted July 26, 2009 The company that worked on the pool drained it so the worker could get access to the tiles. The bubbles that I saw have now popped. There are 5-6 spots the size of my fist that look like the plaster chipped off. Is that the gunite that I am seeing below? Will the pool now leak? Quote Link to comment Share on other sites More sharing options...
quantumchromodynamics Posted July 26, 2009 Report Share Posted July 26, 2009 The tiles are at the top. They should not have drained your pool just to work on the tiles unless there any tiles below the water line. Draining your pool in this kind of heat is just too risky unless it is necessary and the company takes extra precautions to prevent the plaster from overheating. If the plaster has chipped off and you see grey, then you are seeing Gunite. If you see white, you are probably seeing a previous layer of plaster. How many times has the pool been plastered? Just the original time, or has it been redone? The plaster is the waterproof layer, without it, some water will leak out. Some Gunite is pretty waterproof, so you may not get much leaking. The other risk of not patching the delaminated spots is that they will tend to expand. Quote Link to comment Share on other sites More sharing options...
GJJ Posted July 27, 2009 Author Report Share Posted July 27, 2009 Thanks for your help. There was a crack that they also repaired below the water line. The pool has not been replastered in at least 15-20 years. We have lived in the house for 8 years. I went out and checked. The material that is exposed from under the bubbling and flaking off is white. Can these areas be patched? Or do I have to have the entire pool replastered? It would be nice if they could fix it without draining the pool again (this may be a stupid statement). Is that possible? The people that repaired it come back to work tomorrow. They seem reputable. So, I think they will treat us fairly. Quote Link to comment Share on other sites More sharing options...
quantumchromodynamics Posted July 27, 2009 Report Share Posted July 27, 2009 Here is an article about underwater plaster repair. It can be done, but it takes someone who really knows what they're doing. I think that the pool should be drained and thoroughly checked for delaminations. Small areas can be cut out and patched fairly easily. You have to use a diamond blade concrete saw to cut out the entire delaminated section and then patch it with plaster. Plaster that is bonded to Gunite is less likely to delaminate than plaster that is over another layer of plaster. If the total area of plaster that is delaminated is extensive, it is best to have the pool replastered. It may be necessary to remove all of the most recent layer of plaster and possibly even the original layer of plaster. Care should be taken to protect the plaster from rapid changes in temperature. In some cases, it may even be worthwhile to set up some sort of tent to protect the plaster from exposure to direct sunlight. Quote Link to comment Share on other sites More sharing options...
GJJ Posted July 27, 2009 Author Report Share Posted July 27, 2009 Thanks for all your help. Is the repair of the blistered plaster the responsibility of the company that did the work on my pool? Should my position be that they were responsible for notifying me of this possibility when they did not and that they did not take precautions given the heat of the day the work was done? Quote Link to comment Share on other sites More sharing options...
quantumchromodynamics Posted July 27, 2009 Report Share Posted July 27, 2009 The delaminations could have been partly the result of poor procedure on the part of the people who replastered the pool. If the original plaster was not properly prepared, the new plaster would not have good adhesion. Sometimes the delaminated sections fill with water, and when they are heated by the sun, the water expands and causes the bubble to break open. The contractor who drained your pool to work on the tiles should have informed you that there was some chance of finding delaminations and that there was the chance of new delaminations happening while the pool was drained. The contractor should have taken reasonable precautions to avoid causing new delaminations. If the work was done on a very hot and sunny day, then the risk of delamination is fairly substantial. While the pool was drained, the contractor should have thoroughly checked the entire pool for delaminations and repaired them. If the contractor were experienced, they would know this. At a minimum, they should be responsible for draining and refilling the pool. If they took reasonable precautions to avoid causing new delaminations, then you would be responsible for the repair costs. If they did not take reasonable precautions, then they should be responsible for the repairs. Either way, they should have made you aware of the risk. Quote Link to comment Share on other sites More sharing options...
GJJ Posted July 27, 2009 Author Report Share Posted July 27, 2009 The delaminations could have been partly the result of poor procedure on the part of the people who replastered the pool. If the original plaster was not properly prepared, the new plaster would not have good adhesion. Sometimes the delaminated sections fill with water, and when they are heated by the sun, the water expands and causes the bubble to break open. The contractor who drained your pool to work on the tiles should have informed you that there was some chance of finding delaminations and that there was the chance of new delaminations happening while the pool was drained. The contractor should have taken reasonable precautions to avoid causing new delaminations. If the work was done on a very hot and sunny day, then the risk of delamination is fairly substantial. While the pool was drained, the contractor should have thoroughly checked the entire pool for delaminations and repaired them. If the contractor were experienced, they would know this. At a minimum, they should be responsible for draining and refilling the pool. If they took reasonable precautions to avoid causing new delaminations, then you would be responsible for the repair costs. If they did not take reasonable precautions, then they should be responsible for the repairs. Either way, they should have made you aware of the risk. We just spoke with the contractor, and he said to just go underwater and sand them to blend with non-delaminated plaster. The spots are white, so I guess we are looking at plaster not gunite. Is this a reasonable solution? A reasonable response from contractor? Admittedly, our plaster is not in the best condition, but it definitely was not chipping before repairs. Quote Link to comment Share on other sites More sharing options...
quantumchromodynamics Posted July 27, 2009 Report Share Posted July 27, 2009 How thick are the chips that have come up? How deep are the defective spots? How wide are the spots? If it's a full layer of plaster, then sanding won't work. If it's just a thin layer, like less than 3/32-inch, then maybe sanding would work. Plaster is normally 3/8-inch to 3/4-inch thick. Quote Link to comment Share on other sites More sharing options...
GJJ Posted July 27, 2009 Author Report Share Posted July 27, 2009 How thick are the chips that have come up? How deep are the defective spots? How wide are the spots? If it's a full layer of plaster, then sanding won't work. If it's just a thin layer, like less than 3/32-inch, then maybe sanding would work. Plaster is normally 3/8-inch to 3/4-inch thick. It's pretty thin, but I think more than 3/32-inch. I'm going to get a piece when it heats up. Some of the areas are bigger than my hand and growing. Trouble is, it seems there are more and more spots cropping up, so it would take a scuba diver and half a day to sand them. We're getting estimates on replastering this week. Any suggestions there? We've heard the new quartz plasters are much stronger. Quote Link to comment Share on other sites More sharing options...
quantumchromodynamics Posted July 27, 2009 Report Share Posted July 27, 2009 Some of the areas are bigger than my hand and growing. Trouble is, it seems there are more and more spots cropping up, That definitely does not sound good. Sanding won't work. I'm thinking that much of the second layer of plaster may have to be removed. You can scoop up a piece of the plaster with your leaf net. No need to jump in. The quartz is stronger and more durable, but somewhat rougher depending on how the surface is finished. Be sure that the contractor shows you actual samples so that you can feel the texture. I would avoid the pebble. It can look nice but it is too rough for most people. Quote Link to comment Share on other sites More sharing options...
GJJ Posted July 28, 2009 Author Report Share Posted July 28, 2009 Some of the areas are bigger than my hand and growing. Trouble is, it seems there are more and more spots cropping up, That definitely does not sound good. Sanding won't work. I'm thinking that much of the second layer of plaster may have to be removed. You can scoop up a piece of the plaster with your leaf net. No need to jump in. The quartz is stronger and more durable, but somewhat rougher depending on how the surface is finished. Be sure that the contractor shows you actual samples so that you can feel the texture. I would avoid the pebble. It can look nice but it is too rough for most people. Jumped in and pulled up a small piece. About 3/32" thick or 1/8" at most. Sanding definitely is not an option at this point...it is literally peeling up as I moved across the bottom. It would take forever to sand. Here's my question before a new round of contractors come in for bids...is this a cosmetic issue only or does this need to be fixed ASAP. I mean, it is obvious we need to replaster, but we're just wondering if it has to be done now to avoid further damage, or is nothing going to happen if we wait a few months. I'd heard the same thing about pebble tech, so we were looking at the Colorquartz or similar plasters. If you have any recommendations, please feel free to divulge. You've been right on the money so far, and I appreciate the advice. Hindsight, and the pool contractor should have warned us, we should have done the tile work above water line, mastic, and waited to seal cracks until it was cooler. Quote Link to comment Share on other sites More sharing options...
tranders Posted July 28, 2009 Report Share Posted July 28, 2009 Great thread here. Facing the exact same bubbling and flaking here with my plaster pool except I think it was empty and/or drained last year prior to our purchase of the property. It doesn't look pretty and we'll resurface it eventually, but it is fully functional this season so far. As GJJ asks, is it only cosmetic or are there structural concerns? My holes are white and considerably rougher underneath the chips. Quote Link to comment Share on other sites More sharing options...
quantumchromodynamics Posted July 28, 2009 Report Share Posted July 28, 2009 Without looking at it, it is hard to tell how urgent it is. Delaminations tend to spread if they are not repaired. Waiting may increase the amount of plaster that has to be removed. Once the pool is full, delaminations don't spread as fast. Waiting a few months might not cause too much increase in the damage, but it's hard to say. Doing it now is risky due to the heat. Fresh plaster needs to be kept hydrated or it will craze and dry out. If it were done now, I would want some way to block direct sun and a way to continuously hydrate the plaster as the pool is filling. You may want to hire an independent service person to check the plaster and advise you on whether or not it would be best to do it now, or if it would be OK to wait. Whenever it is done, all of the loose plaster will have to be removed and the plaster under the tile and around the fittings will have to also be removed. Since the new plaster will be about 1/2-inch thick, the plaster near any tile or fitting has to be removed out to several inches to allow a smooth transition. When interviewing contractors, ask them if they are prepared to remove all of the old plaster, if necessary. Ask them how they would do it. Ask them what they will do to keep the plaster from getting too hot and how they will keep the plaster hydrated as the pool is filling. Also, have the tile evaluated to make sure that all of the tiles are securely bonded. Any tiles that are not securely bonded will have to be removed and replaced. You can lightly tap on the tiles with the plastic (not metal) end of a screwdriver to tell if they are solid or hollow. The difference in sound is very noticeable. How much of the tile was recently replaced? Just a few, or all of it? Quote Link to comment Share on other sites More sharing options...
GJJ Posted July 28, 2009 Author Report Share Posted July 28, 2009 Without looking at it, it is hard to tell how urgent it is. Delaminations tend to spread if they are not repaired. Waiting may increase the amount of plaster that has to be removed. Once the pool is full, delaminations don't spread as fast. Waiting a few months might not cause too much increase in the damage, but it's hard to say. Doing it now is risky due to the heat. Fresh plaster needs to be kept hydrated or it will craze and dry out. If it were done now, I would want some way to block direct sun and a way to continuously hydrate the plaster as the pool is filling. You may want to hire an independent service person to check the plaster and advise you on whether or not it would be best to do it now, or if it would be OK to wait. Whenever it is done, all of the loose plaster will have to be removed and the plaster under the tile and around the fittings will have to also be removed. Since the new plaster will be about 1/2-inch thick, the plaster near any tile or fitting has to be removed out to several inches to allow a smooth transition. When interviewing contractors, ask them if they are prepared to remove all of the old plaster, if necessary. Ask them how they would do it. Ask them what they will do to keep the plaster from getting too hot and how they will keep the plaster hydrated as the pool is filling. Also, have the tile evaluated to make sure that all of the tiles are securely bonded. Any tiles that are not securely bonded will have to be removed and replaced. You can lightly tap on the tiles with the plastic (not metal) end of a screwdriver to tell if they are solid or hollow. The difference in sound is very noticeable. How much of the tile was recently replaced? Just a few, or all of it? There were a couple of "sections" of tile that were removed and replaced....the spa wall between the spa and pool and then a section about 2' X 2' on one of the bond walls. Also, a few tiles in the corners were replaced where they were loosened. The tile guy did a great job and went around himself and checked every tile to make sure they were adhered well. The sound is definitely different when they are not bonded. The tile should not be an issue. I guess my main concern is that the gunite is not getting wet...that the "new" layer of plaster we are seeing is still waterproof. I really don't care how much of the pool becomes delaminated because at this point, it is obvious we need to replaster. We just want to wait until it's cooler/conditions are better, but we don't want "problems" (meaning leakage, damage to gunite, etc.) to get worse. If it's just cosmetic, if more could delaminate, that's fine. We have a guy coming out today...it will be interesting to see what he says. Quote Link to comment Share on other sites More sharing options...
tranders Posted July 28, 2009 Report Share Posted July 28, 2009 My pool is full of water but the plaster continues to delaminate - or at least flake off. There are are number of visible bubbles that eventually break open and flake away. Perhaps the delamination is no longer happening, but the results are still playing out. Quote Link to comment Share on other sites More sharing options...
GJJ Posted July 28, 2009 Author Report Share Posted July 28, 2009 My pool is full of water but the plaster continues to delaminate - or at least flake off. There are are number of visible bubbles that eventually break open and flake away. Perhaps the delamination is no longer happening, but the results are still playing out. Same here as well...when I went in and walked around, more "bubbles" pooped and chipped off, so I'm thinking it's worse than it looks. Have two estimates coming in today, so I'll pass on any pertinent info I gather. They are replaster companies, so I'm assuming they'll come in with, "you have to repair this ASAP." I'll try to get an honest answer. Quote Link to comment Share on other sites More sharing options...
GJJ Posted July 28, 2009 Author Report Share Posted July 28, 2009 My pool is full of water but the plaster continues to delaminate - or at least flake off. There are are number of visible bubbles that eventually break open and flake away. Perhaps the delamination is no longer happening, but the results are still playing out. Same here as well...when I went in and walked around, more "bubbles" pooped and chipped off, so I'm thinking it's worse than it looks. Have two estimates coming in today, so I'll pass on any pertinent info I gather. They are replaster companies, so I'm assuming they'll come in with, "you have to repair this ASAP." I'll try to get an honest answer. To jackhammer out all of the plaster or not...that is now the question. One company says you just need to sand blast off top layer, the other company says you need to jackhammer it all out. Make it stop please. Quote Link to comment Share on other sites More sharing options...
Jabba Posted July 28, 2009 Report Share Posted July 28, 2009 For what it's worth, I actually find this saga quite entertaining...and educational. We have a plaster/gunite inground pool that I don't think has been resurfaced since 1970 and we're gonna have to bite the bullet here pretty soon. No plaster delamination, but the pool inspector said the previous owner kept the acid level too high and it stained the plaster with the copper from the pipes. Tiles, coping and deck have also seen better days. So I'll stay tuned to your saga and wish you the best! By the way, you just need a 3rd company to advise you so you have a majority. Hopefully there's not a 3rd option they can tell you! Quote Link to comment Share on other sites More sharing options...
tranders Posted July 29, 2009 Report Share Posted July 29, 2009 There's always a third option...and a fourth...and... Quote Link to comment Share on other sites More sharing options...
GJJ Posted July 29, 2009 Author Report Share Posted July 29, 2009 There's always a third option...and a fourth...and... Company #3 coming today...#4 tomorrow, #5 Friday. I'm glad someone finds this entertaining. Quotes so far are through the roof...regular white plaster at about $4750. Crazy. Quote Link to comment Share on other sites More sharing options...
quantumchromodynamics Posted July 30, 2009 Report Share Posted July 30, 2009 Quotes so far are through the roof...regular white plaster at about $4750. Crazy. What does that include? That's not a bad price, at all. Plaster is much more work than most people realize. Quote Link to comment Share on other sites More sharing options...
tranders Posted August 3, 2009 Report Share Posted August 3, 2009 Ended up with some good sized flakes today, so thought I would post them. Real thin they are. As you can see, there is also algae getting in behind the bubbles/delamination and making things worse. http://www1.snapfish.com/thumbnailshare/Al..._NAME=snapfish/ Quote Link to comment Share on other sites More sharing options...
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