Did anything I do cause this plaster damage?

[Agrabah]

When the pool was drained and inspected by the PB and you, did you see other areas of plaster that had delaminated or had cracks? How many small areas have delaminated?
This problem with your plaster has nothing to do with the water chemistry. Neither calcium scaling or acid (aggressive) conditions would cause the plaster to crack or delaminate.
I would insist that the PB make his plaster subcontractor fix the problem.

I didn’t notice any other areas but they patched 3 spots.

I have referenced this site many times and have basically getting waved off being the consumer and not knowing what I am talking about.

 

[onBalance]

Perhaps a better strategy would be to reference the American Concrete Institute and Portland Cement Association which both say that any cracking and delamination (also referred to as "scaling" or "spalling") is caused by workmanship and material defects.
Since both of those groups say that, put the pressure on the plasterer to prove and provide literature from reputable sources that suggests that cracking and delamination, flaking, spalling, etc. is caused by aggressive or acidic water. Also, mention that rain water is very aggressive and acidic and doesn't cause concrete surfaces to crack or delaminate. When concrete does crack, then workmanship or materials is cited as the cause.

 

[ajw22]

Also, mention that rain water is very aggressive and acidic and doesn't cause concrete surfaces to crack or delaminate. When concrete does crack, then workmanship or materials is cited as the cause.

Rain water has a pH around 5 and a TA of 0.

PH Level of Rain Water

Rain water is naturally slightly acidic, witha pH of about 5.0. Natural variations and human pollutants may cause rain to be more acidic. Depending on region, season and presence of pollutants, the pH of rain may drop to as low as 2.0 (the acidity of vinegar).

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