>We have a storage off our deck and keep a generator there. It has gas in it and it has been treated with that stuff to help make it more stable over time. Regardless, I have been instructed to create a small vent in the door to allow vapors to escape. All that said, and knowing that gas fumes tend to hover around the ground, my question is, should the vent be put near the top of the door or the bottom. Does it matter?

Yes. It depends if the gas weights more or less then air. The hole should be in the direction the gas moves. Do it on the highest or lowest point of the room or you will create a trap. Let's hope the door goes outside. And that the rest of the room let move air back in. If you are unsure do both holes.

Agnes