They will work just fine. I move plenty of stuff out here on the farm with blocks of wood and steel pipe. But those farm jacks will lift up to 3 tons. Thats fine if you want to lift the entire thing at once.
My advice, you do one corner at a time,put a piece of wood under the corner, and go to the next corner. You only need to go up 3 or 4 inches. Thats at least a couple stacked Pressure treated pieces screwed together when your done.
Just keep your fingers and toes out of the area, you should be fine.