Please refer to thread286-102863 for information on EN 10204.
Now for U-Mark:
In Germany, your products will only be permitted for the construction, alteration and maintenance of buildings if they bear the U-Mark.

The products concerned are structural materials, construction elements and installations that will be built into permanent structural and civil buildings. Structural materials and construction elements that are permanently connected with the ground (e.g. prefabricated garages, houses) are also affected.

In the near future, new harmonized standards will be issued by the CEN (Committee for European Normation) in Brussels and then will be adopted by the individual EU member states (e.g., in Germany as a DIN EN Standard).

Until the new European regulations are implemented, the German U-Mark must appear on all semi-finished structural materials, construction elements and installations being sent to or used in Germany for structural and civil buildings. The U-Mark will continue to be valid after the CEN regulations are finalized and transformed into national laws. Re-certification will not be necessary.

I hope it helps.

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