Gunite Failure?

[FoundationGuy]

Hello,

I'm a Foundation Contractor and have a business partner that is having a Pool put in. Now I know regulations and requirements are different for pool foundations vs home/commercial foundations but this pool structure has us worried. My business partners wife has been watching/overseeing this project due to we are super busy running two other companies.

Well his pool was shot last week on the 28th and the same day this happened.




It has happened in around 5-6 different locations. These two were the worst locations. Once again I know pools are not foundations of structures but these seem worrisome. What should be the recommendation? Because in my experience things like this will cause issues down the road.

When I talked with the contractor that is doing the pool for my business partner they stated this is normal. He will repair the issues with hydraulic cement and that that is a normal repair for this issue. My contractor has been in business 30 years and came with recommendations but I need help from other professionals in this field. I'm meeting with him Sunday to go over some of these issues with my business partner.

 

[kimkats]

OUCH! What a mess. Do you have any pics that shows the pool with just the rebar before the shell was shot? Need to see what they were working with but I do have some ideas.

 

[JamesW]

Water damage to Gunite shell

A heavy rainstorm came down during the end of our contractor shooting the shell for a Gunite pool. They covered it with plastic but a week later uncovered it and we came home to a hole in the Gunite. Is this repairable?

www.troublefreepool.com

 

[JamesW]

It looks bad.

Did it rain before, during or after the shell was shot?

You should have it core sampled and tested.

Can you see rebar in the concrete?

How thick is the concrete?

What is the psi specification?

What is the thickness specification?

Do you have a trusted concrete testing lab?

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[JamesW]

What is the ground water situation?

 

[ajw22]

That is not normal.

Was gunite or shotcrete applied?

Do you have pics of the rebar work before the shotcrete/gunite was shot?

I would look behind the failed areas and see if rebar behind has been encapsulated as it should have.

 

[JoyfulNoise]

@AQUA~HOLICS or @jimmythegreek might have some thoughts about this …

 

[AQUA~HOLICS]

The failures seem to be at the lower elevations in the pool, possibly the same 10 yard load of materials?
I was unable to make out any view of the rebar cage in the first picture.
Because the material above the failures is still intact it may be due to application.
Shotcrete/Gunite is able to be walked on within minutes of application and only gets stronger with time.
A failure like this may be from either improper application or improper material mixture.
First find out what caused this then you can figure out how to correct it.

 

[FoundationGuy]

Thank you all for the comments so to give updates.

It was Dec 27th not 28th.

Weather that day was

December 27, 2022​

Atmospheric conditions and temperature °F

RealFeel °F

Atmospheric pressure inHg

Wind speed mph

Humidity

Night	+45°	+45°	30.3	0.2	64%
Morning	+41°	+41°	30.3	2	84%
Day	+55°	+55°	30.3	6.9	56%
Evening	+48°	+46°	30.2	3.4	83%

This home is on the north side of Metairie, LA. We do have a high water table as known across all of Southern Louisiana. The contractor is claiming this happens ALL the time and is reassuring us that he can fix with hydraulic cement. My business partner and I have contacted the contractor and mentioned to him we were going to have the concrete core sampled is this the right call? Contractor wasn't to happy about this but we feel it is the best step due to that is what would happen to us if we were pouring a foundation slab. All our slabs are field tested and honestly we have to test concrete during pour as well. But I don't know requirement on pools vs foundations. I will post updated pictures of rebar soon as my Business Partner sends them to me.

 

[JamesW]

I would have it tested.

The contractor should not be concerned about the quality of the concrete.

If they are, they are not confident that it is good.

 

[JamesW]

If the ground water was not well controlled, the mix could get too wet and fail.

Was there water in the pool before shooting the gunite?

Did they put in well points or dry wells?

 

[AQUA~HOLICS]

Having core samples tested is the only way to determine if the material is at fault. Have a sample taken from the failed material in the first picture also tested.

 

[FoundationGuy]

I would have it tested.

The contractor should not be concerned about the quality of the concrete.

If they are, they are not confident that it is good.

If you look in the 4th picture from initial post in the murky water you can see 1. they put in 2 holes they are about the size of the bottom of a 5 gal bucket and about a few feet apart.

 

[JamesW]

My contractor has been in business 30 years and came with recommendations

Sometimes that’s a good sign and sometimes it means very little.

After 30 years, it’s not unusual for the original owner to sell the business and retire.

Many times, the top people will also exit at the same time as their loyalty was to the original owner.

Maybe the original guy was a very good builder, but you never know what you might get from a new owner.

The new owners might be completely incompetent.

The new owners play up the history, reputation and longevity of the company, but the staff is mostly new and incompetent.

Past history is not always a good indicator of future performance.

The company might be 30 years old, but are the top people the same people who started the business?

 

[JamesW]

I would want the engineering testing company to do an onsite inspection of the concrete to take the core samples and to evaluate the job onsite to get their professional opinion.

 

[JamesW]

In my opinion, there is probably about a 20% to 33% chance that the testing company report will say that the concrete fails for specific tests and they will recommend that it be redone.

So, about a 1/5th to 1/3rd chance of failure requiring a redo.

Obviously, this will be a huge deal, especially if the pool builder strongly objects and fights the request to redo the shoot.