TFP has been an invaluable resource for me the last 12 months, and while I've not posted before, I've read A LOT and LEARNED a lot. Thanks to you all, I've had a great experience with my pool. Until this week when MYSTERIOUS wrinkles or creases in my liner appeared overnight! These don't appear to be caused by a floated liner, comparing them to other pictures found on the forum and elsewhere. There are two major creases about midway between liner seams that run the width of the pool. Pictures below:
Here's a close up:
There are a couple of other smaller creases as well. The large creases are about 1/4" to 1/2" high.
Some history may be pertinent also. The pool was installed in November of 2012. It was a warm fall in central NY, but by the time they had the liner installed, temperatures had dropped and there were wrinkles in the floor over the winter. Last spring (2013) the pool was drained and the liner reset by the pool company because of the wrinkle issues. No trouble at all last year with the liner after that, and when I opened the pool last month there were no wrinkles. We had some heavy rains last week (3 to 4 inches over two days), but still no wrinkles. Then about 2 or 3 days after the rains, I rolled the solar blanket back and these huge creases are there. I am befuddled. Can someone please help explain what may have caused this and what can I do to address it? Thanks again.