Advice Needed: Mineral Deposit and Residual Moisture on Spa Tile Grout Line

[lordbobbington]

Hi Everyone,

Long time listener, first time caller

I'm hoping to get some advice on an issue I've been having with my above-ground spa, which has a spillway into the in-ground pool below.

We've noticed an increase in significant mineral deposit build-up and residual moisture on the tile along specific grout lines on the wall where the spillway from the spa flows into the pool below. The grout line and tile in that area stay wet even after the spillway is turned off and the rest of the tile has dried overnight. It's wet to the touch. Cleaning off this build up is challenging, and it will reappear like the photos show after 2-4 weeks.

A few details:

• The tiles are all firmly in place with no looseness when tapped.
• I had a pool tile/grout repair professional out recently. They repaired some small cracks in the grout at the water line inside the spa and some smaller cracks on the spillway itself and the spillway wall.
• Despite these repairs, we continue to see large mineral deposits forming within just 2-4 weeks.
• We live in Southern California and have very hard water, so some build up is expected, but to my eye this indicates a deeper issue.

I'm concerned that there might be a problem where water is getting in behind the grout or tile. Has anyone experienced something similar or have any suggestions on what steps to take next to diagnose?

Thank you in advance for your help!

 

[ajw22]

Welcome to TFP.

It is Efflorescence - Further Reading from water leaking into the gunite and then pulling minerals out as it finds places in your grout to get out.

Your water quality has nothing to do with it.

Show us pictures of your spillway and the inside of the spa taken with the spillway water off.

 

[lordbobbington]

I appreciate your reply! The efflorescence explanation makes sense.

I drained the spa so I could get closer shots of the tile work and plaster inside. I hope this is enough for you to see clearly -- if not, I can snap more photos. Posting two separate times since there's a 10 image limit.

 

[lordbobbington]

Second post, showing the tile work around the inside of the spa and spillway

 

[lordbobbington]

@ajw22 I would appreciate any guidance you could offer. Thank you very much for your time.

 

[ajw22]

I think all of these dark grout lines are questionable and you have may of them among the pictures....

 

[ajw22]

Check corners like here...

 

[lordbobbington]

Thanks @ajw22 the wide dark grout line you circled is an area that was repaired by the pool repair person recently. What precisely should I be looking for? I don't see obvious water entry points there. I'll double check the corners too.