You can create a sufficiently stable foundation for the terrace with 30 x 30 x 4 cm concrete slabs. A slight slope of 1-2% will ensure sufficient water drainage. The spacing of the concrete slabs should be a maximum of 50 cm wide (center of the slab - the center of the slab) and the spacing of the rows a maximum of 70 cm wide (center of the slab - center of the slab). The substructure should be oversized so that it can withstand deformation and does not lift during swelling and shrinkage during the year. Adequate fixing to the foundation is always necessary. The spacing of the timber subfloors should be no more than 40-50 cm (depending on the thickness of the planks). E.g. thickness 21 -22 mm = max. 40 cm and 25 - 28 mm = max. 50 cm. For the timber substructure, only timber of the same or similar density as the supporting timber should be used for uniform swelling and shrinkage.
Aluminum profiles are one of the alternatives to a timber substructure. Compared to wooden lower structures, the profile is completely dimensionally stable and straight. Cracks, twists, etc. caused by climatic conditions, as naturally occurring in building materials such as wood, are eliminated. Thanks to the special shape of the aluminum prism, bolt shear is prevented. Both invisible and visible connection with self-drilling screws into the aluminum is possible.
Thanks to the height-adjustable ECO-Line and PROFI-Line patio targets, it is now possible to lay patio elements simply without mortar. The different support heights of the slab supports and the adjustable targets offer the possibility to correct subfloor height differences without problems and also to cover up unsightly drains and drainage. This creates a level surface with little effort. Surface water that occurs can be quickly and easily drained away using joints.