From a flat slate, you can also make a septic tank ceiling. To do this, we need a metal profile (channel) it is placed from each other at a distance of 50 cm, then flat sheets of slate are placed on top and they, in turn, will pour a cement-concrete mixture with a thickness of 5-7 centimeters, while do not forget to leave the necessary for you holes. This will significantly betray the strength of the roof of the drain pit, and protect in further operation from the possibility of random mechanical damage.
