Crack in pool plaster!

[TimpoolTn2019]

Hi guys, building my own in ground concrete pool, had the plaster done in August, I do not have a winter cover and during a cleaning today I noticed a big crack in the plaster where the pool transitions around a corner from shallow to deep. the pool is not losing water as i have to constantly drain it due to rain. should I be worried? btw.... i am not on good terms with my plasterer as i have been withholding a portion of the payment until they repair tile they cracked and other areas of shoddy workmanship.
Tim

 

[JamesW]

I suspect that it's a structural crack in the gunite and not a plaster issue.

Possibly due to insufficient gunite application or soil instability.

Do you have an engineer advising you on the project?

 

[TimpoolTn2019]

yes and no, I did have the pool designed by an engineer and I did followed the rebar plans when I installed the rebar but that was the extent of their participation. I supervised the shotcrete application and am fairly confident it was applied at the correct thickness. In a phone call I had with the engineer prior to shotcrete she even told me it’s a good idea to put extra rebar at this transition point which I did. the soil was not an issue because we sit on a mountain and a lot of scraping of sandstone was done in order carve out the hole for the pool. I too feel it’s in the concrete, at this point am i just monitoring it?

 

[JamesW]

Maybe dye test the crack to see if it's leaking.

You can patch the crack with pool putty.

Sometimes extra rebar is counterproductive because it can cause "shadowing" behind the rebar where the rebar blocks the shotcrete/gunite.

Hopefully it doesn't keep growing. If it goes up the walls, that's not good.

What was the psi specified for the concrete?

What was the thickness of concrete for the walls and the floor?

 

[TimpoolTn2019]

the concrete PSI was spec-ed at

the walls varied slightly depending on the location but for the most part were 12”, the floor thickness varied from 8” thick to 10” thick.

this crack runs parallel to the wall so hopefully that helps.

 

[TimpoolTn2019]

5000psi

 

[JamesW]

Maybe a gunite/shotcrete application defect. Hopefully, it doesn't begin propagating.

 

[Richard2020]

I have a similar type of issue. I have another post. The crack appeared between the wall and floor joint of the pool. I am monitoring the water level by the hour. It appears that I don't have water loss but too early to tell. Plaster company proposed to repair it. Cut the section, fill with polyurethane and then apply plaster.