Continuing Problem with cracking coping/decking

[jcushman]

Hi all,

I had a pool built in 2017, and have had a continuing issue with limestone coping cracking in one particular area. The pool was finished in July 2017. I first noticed a crack in the vertical side of the concrete decking in May 2018, followed shortly by a crack in the coping above the same area.



I advised the builder, who said it was normal settling and advised to wait until after summer to allow for any additional settling before repair. The first repair was done in June 2019.
There was further broken coping in the same area in September 2019 which was also repaired.


I discovered additional coping cracks and concrete cracks, along with cracked tile in May 2020


One of the owners of the company came out to inspect, agreed this was not acceptable, and committed to repair. Coping section was replaced. A corner of the concrete deck was cut out and filled with new concrete. Everything was painted and the mastic was entirely replaced after these were taken, and everything looked fine. The repair was not able to be completed until October 2020.


In July 2021, cracks again began appearing both in the coping and the side of the deck where the repair had been done.


When I talked to pool builder, their position is now that the cracking is caused by ground movement, is cosmetic, and as long as the shell doesn't leak it is not covered by warranty. They sent me a copy of the contract/warranty. They could possibly repair at our cost sometime in the future. Timing unknown due to how crazy the pool construction business has been for the last couple of years. I am not at all happy with the builder at this point and have let them know.

I would like to get this repaired, but want the repair to last. There seems to be some sort of underlying problem, as this keeps happening in the same spot. I think there is something that is not allowing the deck and pool to move independently when there is contraction/expansion due to heating and cooling of the deck. I am open to any other ideas. I have a few pictures taken during construction of that area if that would be helpful. Thankfully the use of the pool is unaffected, but it is very irritating to have such a large investment not looking as good as it should.

 

[ajw22]

Where is the expansion joint between the pool structure and the deck structure?

You have a problem with the design of the expansion joints which should be there to prevent the cracking.

Expansion Joints and Coping - Further Reading

www.troublefreepool.com

 

[jcushman]

I read your link and am not sure what to say. Here are a couple of pics taken during construction of that area.

 

[ajw22]

This pic makes it look like they tied the rebar in the deck to the bond beam that coupled the deck and the pool structures.

Some of the pics of your cracks look like they originate from the same stress area.

Can you post the pics in a more organized way so I can view them as though I am walking around the area and can place where things connect?

 

[jcushman]

Here are some. The problem area is at the corner near where you can see the step. This is the area where you can see the drain pipe in the construction photo.

 

[ajw22]

Is this joint in red an expansion joint filled with foam backing rod and flexible mastic?

 

[jcushman]

Yes.

 

[jcushman]

Here is a pic of when the decking was done but still had the foam and the mastic had not been installed yet.

 

[ajw22]

You show all the signs of a bad expansion joint.

Hard to say where in the construction they messed up. Your builder is correct it is ground movement causing the cracks. But a functioning expansion joint should not allow movement of the deck to crack coping and tile. Good chance your bond bean will also crack.

 

[jcushman]

Could it have to do with the rebar from the pool being tied to the deck? The problem seems to be right where that one piece of rebar from the pool ties in to the deck.

 

[Orion7319]

Is that normal?

You show all the signs of a bad expansion joint.

Hard to say where in the construction they messed up. Your builder is correct it is ground movement causing the cracks. But a functioning expansion joint should not allow movement of the deck to crack coping and tile. Good chance your bond bean will also crack.

I know nothing about this, but is this normal?

 

[ajw22]

Could it have to do with the rebar from the pool being tied to the deck? The problem seems to be right where that one piece of rebar from the pool ties in to the deck.

Yes, that is what I referring to in post #4.

Nothing should tie the pool to the deck. That compromises the expansion joint.

 

[Orion7319]

Probably a good thing you took photos during construction. Guess somebody forgot to pack an angle grinder that day.

 

[jcushman]

Interesting that all of the rebar from the pool shell was bent down and tied off that way, but the only place there is evidence of a problem is that one corner. I guess it could do with the deck ending there so that would be where the force could dissipate. That whole side of the pool has decking between the pool and the house foundation. The other end where the decking is does not have anything structural on the other side of the deck.

 

[AQUA~HOLICS]

Is the cracked coping in this corner?

 

[jcushman]

Yes it is.

 

[AQUA~HOLICS]

This is how I understand what is causing the coping to crack.

 

[jcushman]

Interesting. There is another pillar on the other side. Has not happened there. Here are construction photos.




So, you think that is more likely than the rebar that ties the deck to the pool mentioned above?

 

[Bill1974]

Is there a chance that water is getting past the liner drain in the deck and causing the soil under it to expand and contract? If the soil under the decking is expansive and water is getting in that could be a contributing factor. Does the cracking happen around the same time of the year? Do you have noticeably dry and wet seasons? The short wall on the pool is going to firmly hold it's place and the highest stress area is going to be where your cracking is occurring. Anther idea is that the expansion joint is not large enough to compensate, but I don't think this is the issue.

 

[AQUA~HOLICS]

Why the other side is not cracking I don’t have an answer for, it could be that the expansion joint on that side is correct and allowing the movement, I do think that the long run of coping between the pillar and the deck that meets the narrow coping in pushing the narrow coping to a point that it’s going sideways and relieving the pressure by cracking and movement.