The structure of every greenhouse has a large area subject to wind and rain. Thus, if you plan to use the greenhouse for several years, the greenhouse needs reliable foundations. The foundation beams offered by Averto have been impregnated under pressure so that they are not endangered by rot fungi which develop in the moist air that greenhouses usually have. Installing the greenhouse on foundations will increase its lifetime.
Before installing the foundation sill, the fertile layer of the soil should be removed and substituted with coarse sand where the sill will be placed. To ensure the stability of the greenhouse and protection from rain and wind, the sill must be secured with piles, which must be driven in inside of the frame at least 40-50 cm deep. If the greenhouse is not too big, one pile in each corner of the sill is enough.
The foundations of a heated greenhouse are built differently. One of the ways is to put the foundation sill on concrete piles which reach a non-freezing layer of ground because the soil cracks if affected by frost. Then the sill is attached with bolts that are casted into the concrete piles. The height of the top foundations should be at least 30 cm. The area between the ground and the foundation beams on which the greenhouse is installed, is filled with pressure-impregnated planks. To reduce the heat loss of the building, the foundation must be insulated. For the insulation to be more effective, the insulation material should be as dry as possible. Therefore, good drainage is necessary.