Plaster Crack

[Pools1801]

We are in the middle of our pool renovation project and are getting close to the plaster step.
When we started the project we noted that there was a hairline "crack" in the plaster that extended down one wall across the bottom of the pool and up the other wall. Now that I have chipped some of the plaster back to tell if there is an issue with the shell I found what appears to be some sort of mastic/putty directly under the crack. It kinda looks like some previous owner tried to repair a crack in the past.

The pool hasn't appeared to leak water yet. I did a water loss test this last year.

My question is should we go all out and have the PB remove all yhe existing mastic and put in staples or leave it and just hope that the new plaster doesn't pull apart again?

 

[Pools1801]

Here are some pictures of the crack.

 

[jimmythegreek]

Can you take some daytime pics amd use something for reference size. Also take a pick amd eat out the putty amd see how deep/wide it actually is.
If it cracked under existing plaster amd transcribed thru to the surface chances are it will happen again. How old is the shell?

 

[Pools1801]

We estimate the pool was installed in '87 or '88.

I have attached pictures of one end of the crack. The other end has water standing now so its harder to get to.

It looks like the crack that transcribed through to the surface lines up with one side of the V cut into the shell. I was careful to not disturb any of the gunite in the shell when removing the plaster/putty. I couldn't find any staples in the gunite, but not sure how far apart they would have been placed. Based on the plaster it looks like this repair was done during the last plastering of the pool. I tried to identify an actual crack in the shell but the only thing I could find was the sharp line on the left side of the V.

 

[jimmythegreek]

Its hard to say not being there. Basically if the shell cracks amd its structural it needs staples. Looks like that was V grooved with a grinder to be filled. Kins of looks like delamination of the gunite in spots. What does the PB have to say about it?

 

[sktn77a]

Definitely needs more than caulking/patching. Staples/rebar to strengthen, concrete on top, then plaster.