Loggia: what must the drainage look like?

Whether balcony or loggia - a drainage must be in both outdoor seating. However, the conditions are slightly different, due to the slightly different construction. You can read about the prerequisites for the loggia in this article.

Loggiaboden as a warm roof

Since a loggia is always built over heated parts of the building, and this closes upwards, but is itself unheated, the loggia technically represents a roof.

Unlike the balcony, where the floor surface has outdoor air contact up and down, this outdoor air contact at the loggia is only upwards. In return, it is protected from the weather and rain, but again better protected than the classic balcony,

From a technical point of view, the flat-roof guidelines are valid for the loggia. 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.


In any case, sufficient drainage must be used for drainage, sufficient to drain the top of the loggia floor to a sufficient degree. 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.

balcony drainage

Regardless of the different structure of the floor and the different conditions can be used in the loggia certainly on 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.

Tips & Tricks

Information on the floor structure of loggias can be found in this article.

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