Hi all -
Our 1961 18x35 gunite pool has been partially drained for 2 months during a major renovation by a pool contractor. We were told that the pebblecoat was in good shape before it was drained. Now, it has developed hairline cracks that emanate from a point in the shallow end. One of the cracks spreads more than halfway to the other side. See the attached photos to see what I mean.
The pool guys claim the cracks were there when the pool was drained. I'm pretty sure I would have noticed the cracks right away, so I'm concerned they've appeared since the water level was dropped.
Please help me with the following questions:
1) What would cause cracks like this? Is it possible they've been there all along, or more likely that they happened since the water was drained?
It is important to note that here in Atlanta it has been unusually cold, including multiple days of hard freezes - teens overnight, staying below freezing during the day. I worry that the temperatures may be to blame somehow.
2) What, if anything, should we do about the cracks?
Frankly, if the cracks are merely cosmetic, I don't care. They won't be visible when the pool is filled. I just worry that these cracks are a symptom of some bigger issue. One theory I have is that water got below the gunite shell, froze, and pushed up to create a pressure point...but I'm no expert.
The current plan is to refill the pool until the water is above the cracks, then do a dye test to see if the cracks draw water in. If they do, my pool guy plans to patch them somehow.
Any ideas you have would be greatly appreciated.
(I searched the forum for these answers but really wanted a direct response based on my photos and questions.)