A plastic cistern resembles a water tank


The key advantage of a plastic cistern is its relatively low weight. The finished parts are usually without heavy equipment to move and can also be installed by private individuals themselves. Modern plastics achieve lifetimes of twenty years. In the case of a high groundwater level, a possible buoyancy due to anchoring must be counteracted.

Ready assembled or individually upgradeable

Among the different types of cisterns, plastic models have a greater variety of shapes than concrete cisterns. The prefabricated components are available, for example, in flat construction, in order to require less deep excavation in difficult ground conditions.

A plastic cistern can be purchased in mountable condition with already prepared inlet and outlet nozzles or individually adapted. For the tanks made of polyethylene or glass-reinforced plastic, the connection options of the cistern can be made with crown drills themselves.

Tightness and garden installation

A plastic cistern is poured in one piece, so that a tightness is given. When installing the cistern, upsetting of the material must be avoided. Thorough and proper processing of all connections and the overflow guarantee tightness.

When asked whether a cistern should be purchased, the type of cistern and their placement plays a role. When the cistern is buried in the garden without a traffic load acting on it, the modern plastics easily withstand the burden of burial and, for example, entering the cover by individuals.

Load capacity and dome shaft

If the cistern is placed under a moving surface such as a carport, a fiber reinforced model designed for that load must be selected. Greater safety in terms of lasting stability provides a concrete cistern. The reputable manufacturers of sufficiently stable plastic cisterns give up to 25 years durability guarantee.

The open top of the cistern, the manhole, should have a large diameter to facilitate maintenance and cleaning. Here, however, attention must be paid to the specific load capacity of this area. A large dome shaft is also recommended especially when mounting a floating extraction.

Properties and purchase decision

When purchasing a plastic cistern, the following factors should be considered:

  • Required excavation depth and soil condition
  • Transportation and costs
  • Recyclable plastic type
  • load capacity
  • Groundwater level and buoyancy protection by anchoring or sheathing
  • Manufacturer warranty
  • Carrying handles or crane eyes for transport and installation
  • Foot construction that prevents twisting after installation

If the cistern is not intended to serve as a water reservoir but is used as a retention cistern, plastic is also suitable as the material. Most manufacturers also offer suitable sets for complete plastic infiltration systems.

Tips & Tricks

If you think about a cistern, you can install a plastic model yourself. Depending on its size, it weighs no more than 500 kilograms; the smallest concrete cisterns start at a weight of more than two tons.


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