Calcium Nodules

[AMH1]

Hello,
I replastered my pool last November (8 months) and been keeping up with pool chemistry and water testing at Lesslie's pool and tips from the good folks on this forum. I have been noticing a few calcium nodules on some of the walls and I scraped them and they have re appeared. I have been reading information online about plaster bond failure and cracks on the plaster and some post states that this will eventually go away as the material under plaster will eventually dry up! I called my contractor and sent them a few pictures and he claims is ""High Calcium". My last pool test and calcium test was within normal range. They will send someone to clean them next week.

I know they chipped around and broke off a big huge areas around my pool and used Bond coat before they replastered the pool. Should I be concerned and is my new pool plaster failing?

Thanks in advance!

 

[reggiehammond]

You need a proper test kit - Test Kits Compared. Without it, you don't know your calcium levels.

 

[Jimrahbe]

A,

You get those nodules when the original plaster has delaminated from the gunite.

It is best to do a full chip out, but it does cost more.

I suspect that that tapping the existing plaster with a hammer only finds very obvious delaminations.

Thanks,

Jim R.

 

[AMH1]

Thank you Reggie and Jim....I will get a test kit and they exacly hammered the entire pool , walls, floors , etc and took big chunks and sections from walls and floor. They did not chip all the way to the bare gunite , cuz he said this is their standard practice.

This is a reputable company in the DFW area. Here's the pic during chipping.

 

[Jimrahbe]

A,

It looks to me like this is the third coat of plaster, maybe more.

I am sure it is their "standard" practice as the problems often do no show up for several years, so why should they care???

Looking at your pic make me wonder about how they know there are no other delaminated areas. It seems it would be impossible to know for sure.

Let's see what Calling @onBalance has to say.

Thanks,

Jim R.

 

[onBalance]

The contractor is wrong. Nodules are not caused by high calcium or even low calcium. It is a bond failure issue between the old plaster or substrate and the new plaster coat. It will take another six month to determine how serious this problem is. Take photos and keep track on the amount of nodules that appear and reappear. I suggest you let the contractor know that he should remedy this problem.

 

[blakeusa]

And a proper replaster should remove 100 percent of the existing plaster to getdown to all hard gunite/concrete shell.
Any cracks or problems with the shell should be repaired, then it get washed down, a bond coat and then the new plaster.
Calcuim nodules are from the OLD plaster coming through the new. If you look at your pictures can you ID nodules where they did not chip out 100 percent of the plaster.
Here is a good article.

Understanding Calcium Nodules in Pools

Calcium nodules in pools are growths of calcium carbonate that ooze from within a pool's surface, but are not directly caused nor cured by water chemistry.

blog.orendatech.com

 

[onBalance]

I forgot to mention another reason for nodules to develop in plaster. Very small nodules can also develop where the plaster shrinks and forms small cracks. In this case, it may not necessarily be a bond failure issue, but simply poor and weak plaster that has shrinkage cracks.

 

[JamesW]

This plaster looks horrible.

In my opinion, it should have been 100% chipped out.

The delaminations might be from the new plaster and/or from the old plaster delaminating from the lower layers.

 

[AMH1]

Thank you James , onbalance, Blakeusa for the great info.....I have sent them emails and pictures , so that it will be documented. I only have a year of warranty and I'm sure they will not do anything AFTER Warranty runs out. So far, it's just a handfull of areas that have the Nodules, but I will keep records and document everything just incase there's more. The nodules are very easy to clean and scrape and with a brush and I don't mind doing that once in a while. But I just want to make sure it does not develop in to Larger Big cracks or have pieces Chip out or Fall off!!!

Looks like I just have to keep an eye and monitor it for a few months and see if the cracks or other areas get affected, right? Thanks again.....you all for the help!