What Could Have Caused This?

[SS05]

I recently had my vinyl liner replaced, had a wall rebuilt and 3-4 posts due to water damage. It's been 6 weeks post-completion. And looking at the pool today, I see the outline of one of the posts and indentation around it.

What could have caused this? I think the dirt/sand was not compacted enough, which was a concern I brought to them more than once when they were packing around that post and under the grass. (We had an indentation issue shortly after the initial install too, but it wasn't this outlined around the post.) We also have artificial grass now, which has indentations close to the pool wall where the issue is. No water has been in the area, except what is in the pool itself.

Any other possible explanations? And any advice on what can be done? (I will be calling the pool company in the morning. But, I'm prepared for them to say it was something my kids did in the 3 times they've been in the pool. Or maybe the small earthquakes we've had...)

Thank you in advance for your help.

 

[kimkats]

That is concerning. Please back up and take a pic so we can see the whole area around that post.

Is there anything in those "posts"? They look like cardboard tubes.

 

[SS05]

That is concerning. Please back up and take a pic so we can see the whole area around that post.

Is there anything in those "posts"? They look like cardboard tubes.

The posts were covered by the dirt/sand. I know they poured concrete inside those cardboard tubes.

Attached are a picture of the old post coming out, and the sand/dirt layer before they installed the liner and added water.

 

[kimkats]

I know they poured concrete inside those cardboard tubes.

So why can't we see the concrete? AND they don't even really touch the boards

 

[SS05]

So why can't we see the concrete? AND they don't even really touch the boards

What do you mean by "they don't really touch the boards?" I don't understand the building process.

 

[ajw22]

What problems are the indentations causing?

 

[SS05]

What problems are the indentations causing?

I have 3 concerns: 1. I'm concerned that the concrete underneath will prematurely rub/wear on the liner. 2. Having sand under the liner gives the floor and sides of the pool a soft, cushiony feel. But in this area, it's hard around the post and feels unsupported in the indentation area around the post. 3. I'm concerned that if the sand/dirt was not adequately compacted, that it'll lead to premature punctures as it settles more, and that the dirt under my artificial grass is also caving in that area, creating a safety hazard for the kids playing.

I don't know what other concerns I should be considering, or how it can be fixed. Or, what I should be asking the pool company to do to remedy it.