What kind of insulation does everyone recommend wrapping around an expansion tank to prevent any freezing damage? I installed an expansion tank next to my hot water heater in the attic last year, and today I was looking through some papers, and I came across a small tag that came with the expansion tank and it had a warning that stated to replace the tank if ever subject to freezing temps (I didn't have it wrapped this last winter). I live in North Texas and winter temps can get to low 20s at night on a rare occasion with averages in low to mid 30s at night. I've closely inspected the tank and the bladder is holding air and seems to be functioning fine. I want to wrap it up for this next winter. Is the .5" thick fiberglass insulation wrap with foil backing adequate enough? The tank is suspended horizontally and supported by metal strapping so a standard tank sleeve wouldn't work too well. Any chance the tank was damaged last winter? Thanks in advance for any suggestions.