When choosing the waterproofing design, cracks in the components that form the waterproofing substrate must be taken into account. Only cracks that occur after the waterproofing layer has been applied or subsequent crack width changes of existing cracks are of importance. This must be able to bridge the waterproofing layer. The following crack classes must be taken into account for the selection of the correct waterproofing type depending on the respective waterproofing substrate:
- Crack class R1-E (low): crack formation/crack width change ≤ 0.2 mm, usually unavoidable crack formation/crack width changes in common waterproofing substrates, e.g. in plinth masonry
- crack class R2-E (moderate): Crack formation/crack width change ≤ 0.5 mm, e.g. in closed joints of prefabricated components, unreinforced concrete, masonry subject to earth pressure and at material transitions
- crack class R3-E (high): Crack formation/crack width change ≤ 1.0 mm and/or crack offset ≤ 0.5 mm, e.g. contact joints of masonry on floor slabs or crack formation on load-bearing components due to unplanned environmental influences such as vibrations caused by construction work
- Crack class R4-E (very high): crack formation/crack width change ≤ 5.0 mm and/or crack offset ≤ 2.0 mm, e.g. due to strong environmental influences (vibrations, earthquakes)
Source: bauwion
