Metal construction is one of the most demanding trades in the construction industry. Precision, technical standards and exact interfaces to adjacent trades are crucial for functional reliability and durability. In practice, however, typical errors are repeatedly found that lead to defects, disputes or functional problems.
As a publicly appointed and sworn expert for metal construction, I see these cases regularly. In this article I present the Five most common execution errors in metal construction and how to avoid them.
Missing or inadequate sealing of connections
Typical problems:
- Missing compression straps or incorrectly dimensioned
- Improper silicone joints
- Connection to seals in accordance with DIN 18531/18533 not available
- Lack of slope formation
Avoidance:
- Correct material selection (compression tape classes, sealants, foils)
- Clarify connection details before installation
- Function test after installation
Insufficient static fastening or incorrect anchoring
Metal constructions transfer considerable loads to the building structure. Faults often occur due to:
Typical causes:
- Incorrect dowels or screws
- Edge distance not maintained
- Insufficient substrate testing
- Non-existent ETA certificates
Avoidance:
- Check load assumptions
- Use approved anchoring systems
- Document fastening plan
- Ensure force-fit installation
Tolerance problems according to DIN 18202 / DIN 18101
Dimensional tolerances are immensely important in metal construction. Even small deviations can lead to malfunctions in windows, doors or sliding elements.
Common mistakes:
- Opening dimensions too narrow
- Fluctuating reveal tolerances
- Lack of compensation through straps or underlays
- Warpage due to improper screw connection
Avoidance:
- Check dimensions several times on site
- Allow for tolerance compensation
- Document assembly steps
Condensation, thermal bridges and incorrect profile selection
A very common problem is damp spots, dripping water or mold growth around profiles.
Reasons:
- Incorrect profile system (no thermal break)
- Insufficient insulating glass values
- Uncoordinated additional profiles
- Lack of drainage
Avoidance:
- Check thermal calculation
- Use thermally separated systems
- Check drainage openings
- Correct glass selection (Ug value)
Missing documentation and evidence
In expert witness cases, it often turns out that a lot has been done correctly in terms of craftsmanship - but there is no evidence.
Typical:
- No assembly protocols
- Missing material certificates
- no photos
- Unclear communication between client and contractor
Avoidance:
- Clear, comprehensible documentation
- Photo documentation of each construction phase
- Testing the materials and systems used
- Handover of complete documentation to the client
Conclusion
Metal construction requires care, planning and detailed specialist knowledge. Many defects are not caused by ignorance, but by time pressure, lack of consultation or poor interface coordination. Most errors can be avoided through consistent inspection and documentation.
Those who want to avoid disputes or uncertainties often benefit from a early professional support or an independent neutral assessment.
Would you like more specialist knowledge about metal construction?
I regularly publish practical knowledge, technical classifications and expert contributions.
I will be happy to answer any specific questions you may have.
Contact us
We would be happy to advise you personally - just contact us.
📞 06131 / 89 39 500✉️ info@metall-sv.de