Whether balcony or loggia - drainage must be at both outdoor seats. However, the conditions are slightly different, due to the slightly different construction. You can read about the prerequisites for the loggia in this article.
Loggia floor as a warm roof
Since a loggia is always erected above heated parts of the building and closes upwards but is unheated, the loggia is technically a roof.
Unlike the balcony, where the floor area is upwards and downwards has outside air contact, this outside air contact in the loggia only upwards. In return, however, it is again better protected from weather conditions and rainwater than the classic balcony. Technisch For the loggia, the flat-roof directive is technically valid. It is according to the definitions for flat roofs to a "walkable warm roof". All structural guidelines for walk-in warm roofs and for flat roof waterproofing must therefore be strictly adhered to. This includes the drainage guidelines.
Slope auf In any case, sufficient drainage must be applied to dewatering, sufficient to dewater the top of the loggia soil to a sufficient extent. How high the gradient must at least be, depends on the local and structural conditions and the precipitation occurring. In some cases it will be necessary to exceed the minimum slope values to ensure adequate drainage.
In this case, there must be an additional ("lower") drainage layer above the slope insulation. A drain mat on a release liner may represent such a layer, for example.
Irrespective of the different structure of the floor and the different requirements, the loggia can also be used with classic drainage systems for the balcony. In some cases, it is appropriate to incorporate such system. In other cases, it will be more likely to use the classic systems for flat roof drainage.