Cracked cantilever coping above the tile line in a fiberglass pool

ba67

Well-known member
Oct 17, 2018
91
Southern Kentucky
The concrete cantilever coping above the tile line in our 18 year old fiberglass pool has been cracking significantly in all 4 corners for several years now. Each spring when we open up our pool, we find small chunks of concrete on the bottom of the pool that have come off during the winter. We’ve been told that the cracking is likely caused by settlement and the pool was likely backfilled with sand instead of gravel which is causing the settlement and cracking to occur.

We cannot afford to get the pool re-set in gravel or get the coping and decking replaced so we are trying to figure out what needs to be done to patch the damage so tiles don’t start popping off. There are no pool renovation contractors in our area and I’m having trouble getting concrete contractors to come over here to give me an estimate. I’ve sent pictures to several local concrete contractors who have given me different opinions on what needs to be done but none of them are available to do the work before we close the pool next month. One contractor says that the cracked areas can be filled with concrete and the coping and decking around the pool can be re-stained so everything matches. Another contractor says that the cracked areas should be filled with caulk instead of concrete because caulk won’t come off as the pool moves like concrete will. This won't look as attractive as filling in the cracked areas with concrete and staining the deck and coping to match, but this contractor claims that caulk is the best solution to our problem since it won't come off as the pool settles some like concrete will.

I’m trying to figure out what needs to be done next year to fix the damage to the coping since none of the contractors I have spoken to have availability until after closing. I also need to figure out if there is anything that we need to do now before we close the pool to keep tiles from popping off during the winter and to prevent more cracking. Any advice would be greatly appreciated.
 

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Cantilevered means the coping is suspended above the pool with a gap between the coping and any part of the pool. It is important to know how the deck was originally constructed to diagnose what is going on.

Because if the deck is truly cantilevered then the pool settling should have no effect on the deck. And any pool movement will not have any effect on the deck.

Have you had any tiles pop off yet?

Are there any signs of uneven water level around the pool?

I don't think your pool is settling.

Those cracks look like what concrete does when water gets into it during the winter and freezes causing the cracks. It is the same process that causes potholes in roads during the winter.



Cantilevered_Coping.png
 
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Cantilevered means the coping is suspended above the pool with a gap between the coping and any part of the pool. It is important to know how the deck was originally constructed to diagnose what is going on.

Because if the deck is truly cantilevered then the pool settling should have no effect on the deck. And any pool movement will not have any effect on the deck.

Have you had any tiles pop off yet?

Are there any signs of uneven water level around the pool?

I don't think your pool is settling.

Those cracks look like what concrete does when water gets into it during the winter and freezes causing the cracks. It is the same process that causes potholes in roads during the winter.



Cantilevered_Coping.png
The pool has definitely settled some according to a fiberglass pool contractor. The settlement caused a leak in the deep end return fitting a few years ago and the cracking started after this leak. The pool is now several inches off level but you can't tell by looking at the water in the pool. No tiles have popped off yet but I'm worried this may happen if the concrete continues cracking and we lose more small chunks of concrete.. I think you are right about water getting into the cracks and freezing because we have a mesh cover that lets water into the pool and we experience more cracking when we have a wetter than normal winter. We try to keep the water below the tile line all winter but it frequently creeps up higher than that if we experience a lot of rain. I'm worried about losing tiles since there are no pool renovation contractors in my town so I want to do whatever it takes to fix the damage to the cantilever coping above the tile line so we don't lose tiles over the winter. Since we are getting different opinions on how to fix this damage, we don't know what needs to be done to fix it. Any advice would be greatly appreciated.
 
I continue to think your pool settling and the coping cracking are two separate problems that are not connected.

It does not look like the coping cracking will cause your tiles to pop off. Pool water over the tiles and getting behind them and freezing will cause your tiles to pop off. To prevent that you need to be prepared to drain your pool with a submersible pump during the winter to keep the water level below the tiles.

I don't have any good fix for your concrete coping cracks. The cracks are already there and are going to allow water in during the winter and cause cracks when it freezes. Any of the proposed fixes that seal the cracks may slow down the cracking. But I don't think any of them will totally stop it. Concrete develops cracks.

The long term fix is to replace the crumbling concrete with pavers or precast coping which does not crack the way concrete does. Concrete was a bad choice for the pool in your environment.
 
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