Winterizing for tile and coping?

[pushin glass]

I have never winterized my pool before, but I'm wondering whether I should start after the record cold this winter. Typically I just run my equipment whenever temperatures dip below freezing, but this winter I noticed a tile joint separate from the others and I think it is secondary to freeze/thaw. I'm guessing that water found it's way into the joint and froze, expanding and blowing the joint during one of our 11 degree overnight lows. I have seen a lot of discussion on this forum about pipes and pumps, but not about winterizing to protect tile and coping. What are your thoughts? Should I start winterizing or will this be more trouble than it's worth?

Also, I asked for expansion/contraction joints to be placed throughout my tile installation but the installer refused. Can't win them all.

 

[Texas Splash]

That's a tough call. We would like to think the waterline tile is watertight at all times to reduce intrusion and such seasonal movement. Yet I suspect moisture will try to seep into just about any gap left open long enough. So even if you lowered your water level below the tile to close it for a few months, it's conceivable that "some" moisture (rain, snow, humidity, etc) could find its way into those areas exposed above the waterline and still freeze/thaw. At least that's what my tiny brain is thinking. I suspect the most optimistic approach would be to inspect/seal any compromised areas before the hard-freezes hit the area.

 

[pushin glass]

The tiles are watertight, but doesn't the grout (unless its epoxy) absorb water and is thus susceptible to freeze/thaw?