Opinions on Saltwater Pool Etching

[windsorpool]

Have a pool thatis six years old now and i have been managing it for 5 now. The first year of its life it was a traditional chlorine pool and im not sure about its first years chemical balance history. When i took over the retirement community that its in decided to go to a saltwater pool and my chemicals have been within acceptable limits for 5 years now with the exception of a power loss, cleaning or drain and fill. About two years ago the plaster started chipping up in the pool and the pieces that are chipping up are coming directly off of concrete below but the pieces are hardly a quarter inch in thickness. I know there is a certain timeline for a new pool that everything has to be done right ex. filling, brushing, sequestrate etc., just wondering if there could have been an incorrect installation. As i stated my chemicals have been correct for years and just wondering if anyone has any insight that could help me withthis contractor.

 

[JasonLion]

There are quite a number of ways that the plaster could have been applied incorrectly, several of which could lead to your current problem. On the other hand, proving it wasn't a chemistry problem is generally quite difficult (unless you have meticulous records of all test results going back to the original install).

 

[RobbieH]

Mine did that before it was a salt pool. I have attributed the issue to a) old plaster, and b) the fact there was almost no CH in the water when I bought the house. There's no telling how long it was like that, either.

 

[windsorpool]

thanks for the replies, ive got great records but they only go 3 years back, but the majority of this problem started in the last 3 years when the chemicals were correct. So if im not mistaking, wouldn't the proper chemical levels prevent any further damage to the surface(which I didn't mention before but I believe is gunite).

 

[JamesW]

If the chemistry were really bad, then the plaster can be thinned and weakened over time increasing the risk of several types of plaster problems. If you can provide some actual chemistry numbers, then we could better evaluate what effect, if any, the chemistry might have played.

These are pop-offs. Pop-offs are delaminated sections, which can be the result of improper installation or other factors. Other factors can include things like:

1) Draining the pool and exposing the plaster to excessive heat or temperature change, which can expand or contract the plaster at different rates than the structural concrete.

2) High ground water can weaken the plaster bond over time. There might not be much you can do about this in some cases.

Once the plaster becomes unbonded from the structural concrete, a void forms and the plaster can eventually pop-off.

If the plaster is only 1/4 inch thick, then that might indicate an installation issue as plaster should be at least 3/8 inch thick.

Member OnBalance is one of the best experts in plaster issues. They have done extensive research on plaster and plaster problems. They have published some very good information, such as this paper.

http://jspsi.poolhelp.com/ARTICLES/temp.pdf