About 40 years' in the architecture & construction biz as a "day job."How do you know all this stuff?
Pressure-treated lumber is your go-to in that case. Which could be as simple are four 4x4 on end in a 2x box frame to keep the 4x4 stable, vertically.just like to add to the elevated block idea, that is a huge advantage in a flood.
Peace of mindHad my sons large Liberty in the garage for several years. Had it on a pallet with no issues. Finally moved it to his home, no signs of rust , corrosion or anything.View attachment 1057999
Getting a new safe pretty soon and will be bolting it down to a concrete floor .
Have heard it might be a good idea to put something under the safe but what a rubber mat ?
Agreed.I have carpet or wood flooring under them but I think being in a climate controlled environment is more important that sitting on something.