Have there been any issues with the weight that these tiles add to structural framing? If I need 50 tiles, at 16 lbs. each, I am effectively adding 800 lbs. onto my wood framing, evenly distributed, of course. In my case, they would not be sitting on a concrete garage/sub-floor, so I did not know if there are structural concerns when using these, especially when adding a power rack, plates, dumbbells, etc. on top of this.