Because of the weight of concrete tanks it is important that the hole into which they will be placed is correctly prepared in advance so that the tank can be lowered directly into the hole when it is delivered to site by the Rain Water Tanks Direct supplier.
The hole needs to be dug large enough and to the correct depth to enable the tank to clear all sides when being placed into hole,. The excavated hole needs to be provide no less than 300 mm clearance between the outside of the tank and the inside of the excavated hole. Some ground conditions or council requirements may necessitate the clearances being greater or the excavation being battered back to ensure no collapsing of the walls of the excavation.
In considering the depth of the excavation, there must be no less than 75mm of blue metal or sand spread level in the bottom of the hole and which will form the base on which the underground concrete tank will sit.
The depth of the excavation depends not only on the tanks height but also its design and also how far below the finished surface you require the tank to be. As Rain Water Tanks Direct supplies a range of tanks from different manufacturers, please discuss your individual requirements with our consultants.