Repairing fiberglass over gunite

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R

rcpilot

0
Jul 2, 2018
14
Burbank
Hi All,

I am in the process of refinishing my pool, a 15k gallon gunite pool that was fiber glassed 12 years ago with new tiles and copings. I have not been good with its chemistry just like my chemistry in college, so now I have a lot of calcium build up on the tiles and many areas of the pool. Currently cleaning the tiles and noticed patches of the fiberglass where it meets the tiles are starting to delaminate. I am cutting away sections that are loose and will be replacing them. The problem I have is that the fiberglass where it meets the tile are super thin around 1/16" or less but a few inches below is around 1/8 inch. Overall the fiberglass walls and bottom surfaces are strong and stable. Do you guys think that I can cut a slot 1/4 x 1/4 along the bottom of the tile so I can have some fiberglass thickness to the edge of the fiberglass? I am hoping with a thicker edge and more surface adhesion will prevent delaminate, or at least last longer. Do any of you think it will weaken the pool's stucture grinding a grove?

Here are some pictures.

IMG_4579.jpg IMG_4592.jpg IMG_4598.jpg
 
Hi All,

I am not sure how thick the cement is in this area but do anyone think it is safe for me to cut a 3/8 x 3/8 grove below the tile so I can tuck in the fiberglass cloth? I am also thinking of embedding a stainless steel rod along the inside of the seams so it would add strength. The rod would actually be wrapped by the cloth while it is wet and then be tucked inside the grove.

I do know I have to sand the top coat of the fiberglass to make sure I have a good bond to the existing fiberglass.

I have not ordered my pool paint yet and do we have a census of the best epoxy pool paint we can use?

Thanks
Vic
 
I have virtually zero experience with everything done to your pool, including what you are proposing, but this would be my concern. From the pic's it looks like whatever the fiberglass is laying on is flush with the tile. Is that plaster? In my pool that plaster would be as thick as the tile plus the mortar adhering the tile to the gunite. Could be 3/8" thick. Could be an inch thick. Gunite is not water proof. The plaster and tile are what make a pool waterproof. I would think one of the weakest points in that water-tight shell is where the plaster meets the tile. So if you cut right there, you're going to weaken the weakest part. And if you happen to penetrate the plaster, down to the gunite, you'll expose the non-watertight sub-structure. Would filling that "wound" with fiberglass and/or cloth and/or steel rod restore that area's strength and water-tightness? If the fiberglass to plaster bond can be made trustworthy in that way, great. But your existing problem suggests that bond was not all that great, which allowed water to seep in between the fiberglass and the plaster, which is what likely caused the delamination in the first place. I'm making a lot of assumptions about how your pool's surface was actually done, but you get the gist...

I understand your logic, attempting to make a more mechanical connection between the two materials. Maybe instead of a slot, I wonder if you could abrase it aggressively in some way, enough to give the epoxy something to really grab on to, but not deep enough to compromise the plaster shell. Scoring or scratching it up with a grinder, maybe?

Using metal might also have its own set of problems. Bonding, rusting, corroding, etc. And the more dissimilar materials you bring together, all with their own expansion/contraction properties: fiberglass, plaster, tile, mortar, grout, steal, and water, the more mischief they'll all get into together...
 
I find it odd that the installer would have had the FG stop below the waterline and then tile above it. You can almost never really seal that connection long term so it would always be a failure point where the FG could delaminate as water seeps behind it. Usually with FG pools the FG extends up above the water line and then the tile is siliconed onto it if you want waterline tile. If you want a longer term more reliable fix I would remove all the tile, FG right up to the base of the cantilever deck, then get new tile and apply it over the FG with silicone. You also use silicone as the grout and it is actually a really strong and clean look.
 
keithw said:
I find it odd that the installer would have had the FG stop below the waterline and then tile above it. You can almost never really seal that connection long term so it would always be a failure point where the FG could delaminate as water seeps behind it. Usually with FG pools the FG extends up above the water line and then the tile is siliconed onto it if you want waterline tile. If you want a longer term more reliable fix I would remove all the tile, FG right up to the base of the cantilever deck, then get new tile and apply it over the FG with silicone. You also use silicone as the grout and it is actually a really strong and clean look.
Click to expand...

Getting the edge of the fiberglass above the waterline makes more sense than what I suggested. If the plaster behind the fiberglass and the tile are, in fact, flush, can he just fiberglass right over the tile, and eliminate the step of having to remove it? Wouldn't he have to put, what, plaster in its place to build up what would then be missing otherwise? Or would the tile not be a good surface to bond new fiberglass to?
 
Such a shame this was not done correctly to begin with. Longshot: I believe here in CA contractors are liable for this kind of construction mistake long after it's done, regardless of contracted warranties. In essence, they have a duty to build things properly, and an obligation to make right anything they do wrong. I don't have the exact facts about this, it's a vague recollection. And 12 years might be too late. But it might be worth a call to the California Contractors State License Board to see if there's anything to be done. The contractor should be fixing this, not the owner.
 
Agree, I did not think about how different materials can have different expansion not to mention there are so many temperature changes between days and seasons. I really need to get a much thicker fiberglass edge and the only place is just below the tile. I will have to grind to get a good bond where it has peeled.

Thanks for the advice!

Dirk said:
I have virtually zero experience with everything done to your pool, including what you are proposing, but this would be my concern. From the pic's it looks like whatever the fiberglass is laying on is flush with the tile. Is that plaster? In my pool that plaster would be as thick as the tile plus the mortar adhering the tile to the gunite. Could be 3/8" thick. Could be an inch thick. Gunite is not water proof. The plaster and tile are what make a pool waterproof. I would think one of the weakest points in that water-tight shell is where the plaster meets the tile. So if you cut right there, you're going to weaken the weakest part. And if you happen to penetrate the plaster, down to the gunite, you'll expose the non-watertight sub-structure. Would filling that "wound" with fiberglass and/or cloth and/or steel rod restore that area's strength and water-tightness? If the fiberglass to plaster bond can be made trustworthy in that way, great. But your existing problem suggests that bond was not all that great, which allowed water to seep in between the fiberglass and the plaster, which is what likely caused the delamination in the first place. I'm making a lot of assumptions about how your pool's surface was actually done, but you get the gist...

I understand your logic, attempting to make a more mechanical connection between the two materials. Maybe instead of a slot, I wonder if you could abrase it aggressively in some way, enough to give the epoxy something to really grab on to, but not deep enough to compromise the plaster shell. Scoring or scratching it up with a grinder, maybe?

Using metal might also have its own set of problems. Bonding, rusting, corroding, etc. And the more dissimilar materials you bring together, all with their own expansion/contraction properties: fiberglass, plaster, tile, mortar, grout, steal, and water, the more mischief they'll all get into together...
Click to expand...
 
You are so right that fiberglass should have been installed behind the tile as well. I think what they did during the remodel was replace the existing tile and then laminated the pool with fiberglass and sanded the fiberglass flush with the tile surface. So what I have is a very thin sharp fiberglass edge. I am really surprised how long it lasted and thinking if they made a slot it would last a very long time.


keithw said:
I find it odd that the installer would have had the FG stop below the waterline and then tile above it. You can almost never really seal that connection long term so it would always be a failure point where the FG could delaminate as water seeps behind it. Usually with FG pools the FG extends up above the water line and then the tile is siliconed onto it if you want waterline tile. If you want a longer term more reliable fix I would remove all the tile, FG right up to the base of the cantilever deck, then get new tile and apply it over the FG with silicone. You also use silicone as the grout and it is actually a really strong and clean look.
Click to expand...
 
Thanks Dirk, I am not sure I can find these guys anymore and if I do, I probably would not want them in my pool working.

I will post pics as I go along. Thanks for the help.

Dirk said:
Such a shame this was not done correctly to begin with. Longshot: I believe here in CA contractors are liable for this kind of construction mistake long after it's done, regardless of contracted warranties. In essence, they have a duty to build things properly, and an obligation to make right anything they do wrong. I don't have the exact facts about this, it's a vague recollection. And 12 years might be too late. But it might be worth a call to the California Contractors State License Board to see if there's anything to be done. The contractor should be fixing this, not the owner.
Click to expand...
 

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You guys mentioned about removing the tiles. Oh man! I have done tile work throughout the house and I am absolutely tired of it. I know it would be the ultimate repair but these tiles where extremely expensive it was nearly $4k added to the pool's remodel. My wife would kill me if I told her I need to remove them, LOL.

I think I can pretty much seal the tile with fiberglass by having a deep enough grove.

In the meantime, I will be heading off to the hardware store and get a carpet runner of some sort cause this darn pool is dangerous to walk on.
 
Almost done cleaning the pool tile, I have tried soda blasting but it was not cutting it at all. Using glass bead certainly does a good job but I have to be careful with it as is taking some of the sheen of the tile glaze. I recycled the beads and get around 70-80 percent return.

I have tried posting pics and I am getting exceeded quota? even reducing the size of the pics.. I was able to initially post pics at the start of this thread

I have also made a channel under the tile using a 1/4" thick stone wheel grinder.

pics would be nice...
 
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More importantly, we gotta have pics!! ;)
 
This took me a little over a month mostly working alone on weekends, I had help one day with sanding the pool and help from my son during the painting. Painting took around 3-4 hours per coat. I spent around $2000 for this project, half of that was for the epoxy paint. I was quoted $4600 with a 1 year warranty from one of the local pool company (1 year warranty did not make feel right about at all), and that did not include repairing fiberglass. There were a lot that would not touch it since it was fiberglass and painted. Now will see how long I have till it needs a new coat of paint.
 
Thank you Keith! I am pretty happy how well it turned out.

Well it took 3 full days to add water with a garden hose, I am sure I will get the bill at the end of the month. I have added pictures to my Google Photo page.

I used to have a solar pool heater above my garage but it was removed when the garage was redone. It worked great and pool temp can get +10 degree. It did however made my pool pump worked a lot harder and I had to replace it.

Currently trying to figure out how I can plum a new solar pool heater without using my pool pump as in Cali it is quite expensive to run the pump during the day than in the evening. Planning on using a solar panel (100Watt) to run a 12v motor to pump the water to the solar pool heater. I want to bypass the pool pump and filter to prevent any restrictions. Solar heating will be completely free after the initial cost of the items I need.
 

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