Yes,...

...they should be. Only approved and tested WW mortar in accordance with DIN 19573 should be used for every sewer renovation and the new construction of a wastewater structure. Basically, the problem is often that untested and unsuitable materials are used in new construction, which is why we find the damage that occurs in sewer renovation.

For example, we very often see in masonry sewers that although a sewer clinker was used that can withstand the demanding requirements in the wastewater sector, the joint has been damaged by corrosion or heavy mechanical loads and cannot withstand these.