I have my tank on wood. I make sure there is space under the stand so that it doesn't sit on the floor directly. This lets air flow through there and also lets me get a towel under there is any water spills. I put a towel down when I'm doing water changes.
my tank is on the hardwood. it is only a 66 gallon tank so it isnt massive. the stand is set upon those dense fiberous slider material pads so there is a very slight gap underneath. it was this way at my old house and when we moved after a year, you couldnt tell it was there. I wiped up spills quickly when they happen. this was on solid hardwood. we have engineered hardwoods in the hew house and i have not had an issue yet.