Experts for cultural heritage preservation and building protection are setting an example in the old Hanseatic city of Wesel, Germany. A special protective layer is being applied to the outside of Willibrordi Cathedral, which was built in the late Gothic style, in order to protect the city's famous landmark against damaging environmental influences. Modern “rain jackets” play an important role: in a similar manner to the breathable protective clothing worn by athletes, moisture should be able to escape from the inside to the outside of the building but, at the same time, wetness on the outside of the building should not be able to soak through to the inside.
Experts from the Essen-based specialty chemical group Evonik have utilized the principle. Their solution for the cathedral is called PROTECTOSIL®. The clear, water-repelling liquid that is manufactured with this product can be applied to brick surfaces, where it is absorbed and then offers protection against pollution and building damage caused by moisture and other environmental effects.