Help me understand how drainage works on these tiles if you advise to put a weed barrier down and then glue the tiles together over dirt? Would that not prevent drainage?

The weed barrier would not prevent the water to flow through our Flagstone Rubber Pavers. The paver itself is semi-permeable allowing water to flow through the tile. The water would then hit the weed barrier and flow through the dirt below since most proper weed barriers are porous. The glue between the tiles just ensures the flooring performs properly in both hot and cold weather.