• There must be a distance of at least 1.50 cm between the nearest construction wall and the pit.
  • A smooth ground should be prepared for the pit, free from stones and similar sharp-edged objects.
  • It must be approved by a civil engineer that the ground is not swampy and has load-bearing properties.
  • It is recommended to level the ground with a 5-10 cm thick sand bed.
  • The pit where the PE Underground Storage Tank will be placed must have dimensions with a minimum of 1-1.20 meters added to the width or diameter of the tank, with a minimum of 50-60 centimeters on all sides, including the safe working margin according to the ground class. (Here, the table width of the compactor or compression tool used for back compression is essential.)


  • PE underground storage tank should be placed on smooth ground.
  • The base on which the PE underground storage tank will be placed should be thoroughly compacted and leveled using 10-20 cm high fine sand.
  • Before leveling, if the natural excavation ground is not good (watery, loam, etc.), improvement is made with 0-50 mm dry crushed stone material.
  • In cases where the ground water level is high, a smooth concrete base with a height of 15 cm should be created using C18 or C20 class concrete, if deemed necessary by the competent civil engineer. The PE underground storage tank should be fixed to this concrete.


  • After the connections are made, the tank should be filled 2/3 with water.
  • The distance between the tank and the pit wall should be filled with sand (C in drawing 2) in layers, up to the water inlet & overflow outlet connections of the tank, and the compaction process should be done by a qualified personnel and, if possible, with a hand compactor.


  • After the installation works are completed, light filling material (material density < 1.7 t/m3 | B in drawing 1) should be covered up to the top of the tank.
  • The last layer, approximately 20 cm deep, should be filled with surface soil that is also free of stones and similar hard materials.
  • During the filling process, the area around the inspection manhole should be coated with fine sand.
  • The inspection shaft and its cover are only open to pedestrian traffic, and in order to be opened to vehicle traffic, it must be supported by another inspection manhole and cover solution with a concrete collar suitable for this purpose. It is recommended that you get support from Floteks A.Ş. for the solution.
  • Applications in areas where the tank is at risk are subject to special conditions, as it may damage the tank under some conditions.
  • These conditions have been determined by a competent civil engineer or it can be recommended to the customer by Floteks A.Ş.
  • In cases where the underground water level exceeds the tank floor level, measures such as anchoring the tank to the ground may be required, so Floteks A.Ş. or a competent civil engineer should be consulted.

The burial process of the Floteks Subterra PE underground tank series must be carried out within the framework of the conditions specified in the “Subterra PE underground tanks technical application manual”, which is supplied with each tank and which you can obtain at any time.