Abstract: A floor for a cultivation area such as a greenhouse. An accommodating hole is excavated in the ground and a flexible holder for liquid such as water is placed therein. The top of said holder is provided with a supporting plate. By varying the level of the supporting plate, the level of the greenhouse floor is varied. The water can contain heat. Optionally there can be a further holder which, for example, contains liquid with different properties, such as a different temperature. A number of such holders can be incorporated in a greenhouse floor.
Abstract: Greenhouse construction consisting of a number of rooves with supporting members, such as longitudinal beams, ridges and gutters. These supporting members are provided with rails for moving a carriage or the like over them. The rails and supporting members provide each other with structural strength so that a relatively slim construction with no or hardly any restriction in the light level in the greenhouse construction occurs.
Abstract: Roof construction for a greenhouse has two roof elements positioned at an angle, wherein first and second members extending between ridge and gutter are fitted in each roof element. The second members extend perpendicularly to the ridge/gutter and are members taking compressive load, while the first members joined thereto are members taking tensile load. There are tensioning members to introduce tension and pressure, respectively, into the construction. With this arrangement a particularly rigid whole is obtained. The tension members can be joined to ridge and gutter, but it is also possible to construct these with a shorter length.
Abstract: A floor for a cultivation area such as a greenhouse. An accommodating hole is excavated in the ground and a flexible holder for liquid such as water is placed therein. The top of said holder is provided with a supporting plate. By varying the level of the supporting plate, the level of the greenhouse floor is varied. The water can contain heat. Optionally there can be a further holder which, for example, contains liquid with different properties, such as a different temperature. A number of such holders can be incorporated in a greenhouse floor.