Creases in liner

[63deejay]

We have just moved into a house with an indoor heated pool with liner. The liner is around 10 years old. The previous owner drained the pool and we have now refilled it. Initially everything seemed ok but when we were away on holiday I turned the heat off and during that time several large creases have appeared in the liner. The pool has a brominator and water test results are.
Ph: 7.4
TA: 140
Bromine: 1 ppm
Calcium hardness 140

Could turning the heater off cause the liner to crease or is it simply the liner is old or is there any other possible causes ?

Thanks

 

[Swampwoman]

Greetings. I'm no expert on indoor pools but maybe someone who is will notice this thread. I do have an old liner, though, and I have noticed on mine there are a few vertical wall wrinkles that only turned up when the heater was shut down for a week while it was being replaced. At 15 years old, mine is getting changed next week, but due to color fade in hopper, not the wrinkles

In general, creases are most often caused by ph being too low (acidic) for a spell, which then causes the liner to get a bit waterlogged/stretched then loose again on degradation. This may have happened during previous ownership (as mine theoretically may have...it was a foreclosure and sat for 2 years with h /TA completely crashed at 4.5.) Or it may be a sign of age

Your ph, however, is not currently super low. I'd expect an indoor liner to have a lot more life in it than an outdoor, so if the wrinkles aren't too bad, your likely fine for a good while yet. But it is a sign that either the vinyl has degraded a bit.

 

[basod]

I had a few creases appear after my main drain failed in the dead of winter and the pool completely drained. During the hasty refill to prevent any collapse I reopened to a long crease in the shallow end floor. Over the course of the summer it worked its way out with no pool heater. It seems counterintuitive that a cold vinyl liner would develop wrinkles - it should be contracting not expanding. It's likely there is different friction coefficients under the liner that cause non uniform expansion & contraction movement. This is especially true if the wrinkles occur near a fixed point like a return, skimmer, drain cover.
There is a pliability aspect going on as well with a cold vs warm liner and if it sees sun in one area causing localized heating with no pump running the liner expands in one area but remains cooler and less flexible in an adjacent section.