new limitations for concrete

[Thales7]

what is: singularity about use of concrete and brick floor. example: it's not possible put concrete on water.

why use: to turn the game more realistic and allow on ores without looking the ores.

how it's work?: imagine that concrete can't put under natural entities (rocks and trees) but around than, like in water. And not under ore but cover on than until be uncover, turn off the resources in appear and function (the ores cover can't be mining or be seen).