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German Wet-Room Waterproofing: Check DIN and Land Rules

Plan wet-room waterproofing against the applicable Land rules, DIN 18534 parts and the chosen product system. The old Bauregellisten are archived.

DIN 18534 (applicable parts and editions to be confirmed) Clause DE DIN 18534

The requirement

Start with the building law and technical rules in force in your Land. Then check which DIN 18534 parts and product rules apply to the wet room. A standard’s name alone does not tell you its legal scope on your job.

DIBt publishes the model technical rules, called MVV TB. Each Land puts its own version into force. DIBt also tracks that progress. The old Bauregellisten are in its archive, marked as repealed from 1 April 2019. They are not a sound basis for a claim about current wet-room law.

Bavaria’s ministry explains the link clearly: a technical rule becomes binding under building law when it is brought in as a technical building provision. Check the adopted text, its scope and its changes. Contract terms may call for a standard too.

Plan the wet-room system

DIN 18534 covers waterproofing inside buildings. Get the parts that match the work. Check each part’s edition. Do not assume one revision date applies to the whole series.

The full standard text was not checked for this guide. We therefore do not give a design water level, membrane height or fall ratio from it. A number from a trade summary is not a verified limit for your room.

Ask the designer to record these points on the plan:

  • Which water exposure class applies to each floor and wall.
  • Which base, seal and finish form the chosen system.
  • How the seal joins the drain, pipes, door and nearby walls.
  • Which falls and levels must be checked before the finish goes on.
  • Which product records and site checks must be kept.

Use the product maker’s instructions with the design. Check primer, coats, drying times and joint details. Keep photos of work that will be covered. A bag of tile adhesive is not a full wet-room design.

Sources

Related building rules