A carefully prepared greenhouse substrate is essential for the stability and service life of the frame, wall and window elements as well as the roof construction. The frost-proof design supports the plants in growth and helps to minimize heating costs in winter.
What should you consider when preparing the greenhouse substrate?
A well-prepared greenhouse substrate is essential for stability, longevity and plant growth. The frost-proof design includes the excavation of a construction pit, an insulated ring foundation made of concrete with a depth of 70-80 cm and the use of moisture-resistant rigid foam.
Even if it is a relatively small and usually not very heavy structure, thegreenhouse subsoil must be stable and load-bearing and therefore requires particularly good preparation. Neither a self-assembled nor a prefabricated house may simply be placed on the ground, as this damages the stability and also the plants due to the associated leakage near the ground.
A stable base ensures a long service life
While when building your own it is up to you whether you choose a wooden, concrete or brick foundation as a solid basis for walls and roof construction, prefabricated houses usually come with a precise foundation plan that is used for assembly work is binding and must be observed. We have already reported on the various options that are common when building a foundation. From a structural point of view, the foundation as a greenhouse subsoil has the main task of absorbingall horizontal and vertical forces of the superstructure. Nevertheless, it also plays an enormously important role, which will be essential for the later growth of the plants and may even ease the burden on your wallet.
The thermal function of the greenhouse underground
Even though we have only been able to enjoy relatively short winter impressions in our temperate Central European latitudes in recent years, longer and more severe frost periods should never be completely ruled out in the future. With normal soil structures, the frost line in the average garden would be at asoil depth between 70 to 80 cm If you carefully prepare your greenhouse subsoil to these dimensions, you have a good chance that the interior will remain essentially frost-free, even without heating and that the possible heating costs incurred for air conditioning are kept to a tolerable level.
Preparation of the subsurface
Especially with planned ground-level planting, digging a “pit” will definitely pay off during later use. A concrete ring foundation insulated with rigid foam panels to a depth of 70 to 80 cm ensures that the geothermal energy can rise unhindered, so that there will normally be no ground frost even in unheated houses. The temperature measured on the surface in such houses is on average 3 °Ceven during longer periods of frost
Tip
For insulation, only use hard foam panels (€13.00 on Amazon), which are moisture-resistant and root-proof, which is not the case with Styrofoam panels, for example.
