In the "Technical Rule for Roofing with Roof Tiles and Roof Tiles" from the ZVDH (Central Association of the German Roofing Trade), a standard roof pitch is specified for each roof tile/roof tile shape depending on the type of roofing. This specifies the smallest inclination of the roof up to which the respective covering has proven to be rainproof in the practical test , without any special requirements for the sub-roof.
The standard roof pitches specified in the technical data sheets of the individual products sometimes deviate from these values and are then decisive for the respective product. In conjunction with certain additional measures, the standard roof pitch may also be undercut up to the so-called minimum roof pitch. These additional measures mainly concern the design of the sub-roof.
Source: bauwion
