Water tightness against driving rain

Driving rain is a combination of wind and rain. The building element is exposed to water and pressure.



When testing tightness against driving rain , the building element to be evaluated is mounted in a subframe (steel or wood), the building connection joint is sealed and clamped onto the test stand with the outside facing the direction of the spray nozzles.

The driving rain load consists of the effect of wind and rain, so that the requirements for driving rain tightness to be specified in the planning must be derived from the expected wind load on a structure. Tests for driving rain tightness are carried out in accordance with EN 1027 and the results must be stated in accordance with EN 12208.

The proportion of the wind load when exposed to driving rain is therefore derived from the wind load according to DIN EN 1991-1-4 and DIN EN 1991-1-4/NA. Thus, in order to determine the requirements, the design wind load according to DIN EN 1991-1-4 and DIN EN 1991-1-1-4/NA must first be determined and reduced for the requirements on driving rain tightness according to Table 8: Stress classes for windows, source: Table A.1 DIN 18055:2014-11, correspondingly).

The procedure is as follows:

  • Determination of the rated wind load from the stability verification of buildings according to Annex A.
  • Determination of the proportion of the wind load to the driving rain load. According to Annex A of this guideline, it is to be assumed to be 25% of the design wind load.
  • Classification of the driving rain load on the basis of this reduced wind load in Table 9 to determine the class of driving rain tightness.
  • When determining the class, the installation situation is to be assessed according to protected or unprotected position.

Depending on the building element and the class to be achieved, the surface of the building element is sprayed with water under positive air pressure. The amount of water is 1-2 l/min m² per nozzle and depending on the method. In some cases, a distinction is made between method 1A = unprotected installation and method 1B = protected installation.

Testing is carried out until a flowing water ingress is detected in the area to be protected or the required class has been reached. The number of nozzles used depends on the size of the test sample.

Depending on the type of building element, driving rain tightness is tested as part of a combined test, air permeability, driving rain tightness and wind load.

The test can also be carried out on external, DAkkS-calibrated test stands on site at the manufacturer.

Building elements / standards

The following components can be tested and classified:


Building element Test acc. to Classification acc. to.
window – DIN EN 14351-1

external doors – DIN EN 14351-1

internal doors – DIN EN 14351-2

DIN EN 1027 DIN EN 12208
facades – DIN EN 13830 DIN EN 12155 DIN EN 12154
gates – DIN EN 13241 DIN EN 12489 DIN EN 12425

Your component is not listed? Please ask us!


Requirements using the example of windows and doors

Class acc. to DIN EN 12208 (method 1A) Class acc. to DIN EN 12208 (method 1B) Test pressure [Pa] duration
1 1A 1B 0 15 min
2 2A 2B 50 line 1 + 5 min
3 3A 3B 100 line 2 + 5 min
4 4A 4B 150 line 3 + 5 min
5 5A 5B 200 line 4 + 5 min
6 6A 6B 250 line 5 + 5 min
7 7A 7B 300 line 6 + 5 min
8 8A 450 line 7 + 5 min
9 9A 600 line 8 + 5 min
10 Exxxx Above 600 Pa in steps of 150 Pa, the duration of each step must be 5 min.


Minimum requirements in Germany

Requirements according to class / limit values



Andreas Nerz
Water tightness against driving rain
08036 674947 - 0
Kontakt aufnehmen
Christoph Geiger
Water tightness against driving rain
08036 674947 - 0
Kontakt aufnehmen
Günter Borrmann
Water tightness against driving rain GATES
08036 674947 - 0
Kontakt aufnehmen