Point well taken! "Water damage" can be as egregious as any damage imaginable, especially to metal and paper products. I am lucky in that where my safe now stands, (and it weighs in at approx 1500 lbs empty) is a solid concrete foundation member 9 feet wide. The wall behind the safe is sheet rock facing over an approx 1 ft concrete wall. "Water damage" is something I am "hoping" can be precluded (but forgot about) as this safe has heat activated expanding gaskets as you describe.
Thanks Mike, lloyd