If you are asking about the correct gradient. It is 1:40 (meters)
tile should slope sightly down toward the drain and drain should be recessed slightly below the top of the tile
They share the same drain and it is becoming clogged. Drain cleaner in both drains should help.
insert a high pressure sprayer to wash out dirt.
A floor drain , drains water and other liquids that spilled on the floor.
On any car, they are usually in the center of the floor pan on each side and front and back. You will have to remove the carpet to get to them since they are put in from the inside. You should be...