Different types of substructure
Distinctions between different types of substructures are similar to the differences in subsurfaces: here, too, we differentiate between floating and solid installations. Solid substructures are screwed firmly to the subsurface – but floating substructures cannot be screwed to the subsurface.
Design of the substructure on a solid subsurface
Solid substructures can be split into those that sit on even, full supports and those that are installed on uneven supports that do not cover the full area of the substructure. For example, this includes concrete or installing the terrace on top of an existing terrace. To even out the levels on concrete, we recommend cement, packing plates or packing pieces as spacers.
Design of a floating substructure
With floating substructures the subsurface can be solid or consist of a sufficiently stable, compressed layer of material, such as gravel, ballast, aggregate, etc. A frame is used to form this subsurface. The level of a floating installation on top of a solid subsurface, such as wooden beams, a concrete foundation, steel posts with steel supports or a concrete strip footing, can be balanced out by the substructure itself or by adjustable supports. If the subsurface is gravel, ballast, or aggregate, the level is balanced out with standpipes filled with concrete, concrete slabs or post supports concreted in place.
Special features of a roof terrace
A roof terrace is also supported with a floating substructure. The special feature with a roof terrace is that wind loads also have to be absorbed in addition to the bearing loads. Because of this, additional concrete slab anchors may have to be installed as loading. The level can be balanced out with concrete slabs or bags filled with cement.