A contractor’s warning should explain the technical concern and its likely consequences. A generic reservation is much less useful than a specific, timely communication.
Archive article, reviewed and updated on 12 November 2026. The original publication date is retained.
The 2021 Brandenburg decision
In its judgment of 29 July 2021, 12 U 230/20, the Brandenburg Higher Regional Court set aside the first-instance decision and remitted the dispute concerning paving and drainage works. The decision should not be reduced to a promise that a verbal warning always eliminates liability.
A practical notice process
Identify the concern, the affected design or prior work and the foreseeable consequence. Address the notice to the appropriate recipient, follow the contractual form and preserve receipt. If the employer insists on proceeding, assess the effect of that instruction and any safety implications.
Four practical examples
Illustrative scenarios: the appropriate steps depend on the contract, evidence and applicable law. These are not reports of client matters.
An unsuitable substrate
Describe the specific compatibility problem before covering it.
Insufficient drainage depth
Explain the likely consequence for the proposed installation.
A verbal site discussion
Confirm the warning accurately in the required form.
Instructions to proceed
Record the response and assess whether execution remains legally permissible.
Further guidance
Legal framework & further reading
Reviewed: 12 November 2026. Statutory references are to German law unless stated otherwise.