The check topics in this guide are compiled from TS EN 1090-1/2 steel structure conformity standard, TS EN ISO 3834 welding qualification, EN 10346 galvanized coating standard and AYD Prefabrik light steel field practice.
Standards in light steel production are updated periodically. Before the contract, current versions should be confirmed with the manufacturer's technical office.
TS EN 1090 certificate: the core identity of a light steel manufacturer
TS EN 1090 is the European standard regulating the conformity assessment of steel and aluminum structural components. Every facility producing light steel houses must hold the TS EN 1090-1 manufacturer conformity certificate and operate per the TS EN 1090-2 execution requirements.
The certificate is issued after a facility audit; each plant has its own. A dealer or seller cannot inherit it. The certificate number and validity must be checked before the contract.
- TS EN 1090-1 is issued separately for each production facility.
- Certificate number and validity should be verified.
- Dealer answers like "the partner factory has a certificate" are not acceptable.
- The execution class (EXC1-EXC4) must match the project.
Profile wall thickness check: a millimeter difference affects the structure
Light steel profile wall thickness is typically in the 1.2-2.5 mm band, and the structural design is calculated directly on this thickness. The thickness in the contract must match the produced profile exactly; even a 0.2 mm difference shifts performance.
Profile tensile tests verify real strength in the lab. Asking the manufacturer for the lot-based test record book is a standard control.
- Profile wall thickness should be specified in mm in the contract.
- The produced profile can be measured with a caliper on site.
- Profile tensile reports should be retained per lot.
- A 0.2 mm deviation distorts the structural calculation.
- Test reports should be archived for at least 5 years.
Galvanized coating quality: Z275-Z350 band and certificate
Corrosion resistance of light steel profiles is provided by galvanized coating. Per EN 10346, coating mass is expressed as Z275 (275 g/m²) or Z350 (350 g/m²); Z275 is the minimum recommendation for housing, Z350 is ideal for coastal and high-humidity zones.
Galvanized certificates can be requested per coil. A light steel manufacturer that retains galvanized reports in its raw material supply chain shows fundamental quality management.
- Z275 is the standard, Z350 is recommended for humid climates.
- Galvanized certificates should be requested per coil.
- EN 10346 galvanized standard reference must appear in the contract.
- If galvanized thickness is insufficient, corrosion starts early.
- Post-galvanizing processed points are exposed to corrosion and require protection.
Welding qualification and CNC cutting accuracy
Welds are the critical link of structural safety in light steel. The TS EN ISO 3834-2 certificate indicates a high level of welding quality management; at house scale, TS EN ISO 3834-3 is also acceptable.
CNC cutting accuracy should be at the ±1 mm level. Low accuracy creates profile mismatch and additional installation labor on site. Calibration records and a cut test piece can be requested.
- TS EN ISO 3834 welding qualification should be asked.
- Welder qualifications (WPS/WPQR) must be retained.
- CNC cutting accuracy should be at the ±1 mm level.
- Calibration records should be updated annually.
- A cut test piece sample can be requested.
Factory capacity, production speed and certificate summary
The manufacturer's monthly m² capacity and the number of parallel projects determine your delivery time. Low-capacity manufacturers may offer low prices, but the delivery discipline risk is higher. Monthly capacity should be requested as a number and the production plan shared in writing.
TS EN 1090, TS EN ISO 3834, ISO 9001, galvanized reports, profile tensile tests and welder qualification certificates should be evaluated together. The contract should not be signed without seeing all of them on site.
- Monthly production capacity should be written as a number.
- The number of parallel projects should be asked.
- TS EN 1090, ISO 9001 and TS EN ISO 3834 should be requested together.
- Galvanized and profile test reports should be attached to the offer.
- Document validity dates should be checked before the contract.
Related pages
Frequently Asked Questions
Can we work with a manufacturer without TS EN 1090?
Not recommended. TS EN 1090 is the core conformity standard for light steel production in Europe; without it, structural safety has not been audited. The certificate number and validity must be verified before the contract.
How is profile wall thickness checked on site?
A sample taken from the production line can be measured with a digital caliper. Lot-based profile tensile reports should also be requested. A deviation above 0.2 mm between the contract value and the produced profile is unacceptable.
What is the difference between Z275 and Z350 galvanized coating?
The numbers represent zinc mass per square meter. Z275 = 275 g/m², Z350 = 350 g/m². Z350 provides thicker protection and is recommended for humid and coastal areas. Z275 is the standard for inland zones. The certificate should be retained per coil.
Which document should be requested for welding qualification?
TS EN ISO 3834 covers the manufacturer's welding management system, while WPS (Welding Procedure Specification) and WPQR (Welding Procedure Qualification Record) cover each procedure and welder's qualification. All three should be requested together.
Why should CNC accuracy be at the ±1 mm level?
Light steel profiles are cut in the factory and assembled on site. Deviations above ±1 mm create profile mismatch on site, leading to rework, lost time and extra cost. Higher accuracy speeds up installation.
How does monthly capacity affect delivery time?
If the manufacturer's monthly m² capacity is limited and multiple projects run in parallel, your job will be queued and may slip. Capacity should therefore be requested as a number and the production plan added to the contract in writing.
See our light steel production line
On the AYD Prefabrik light steel line, profile tensile tests, galvanized coating checks and CNC cutting accuracy can be observed in person. Contact us for a facility visit.
