Knowledge base · APK
Rust and the APK: when is corrosion a rejection point?
A rust spot on a door looks ugly, but the inspector shrugs it off. The same brown layer on a chassis rail can fail your car. The difference comes down to one word: load-bearing. Here is how the APK judges rust — and how to spot the places that matter yourself.
Cosmetic versus structural
The APK is a safety inspection, not a beauty contest. Rust on doors, wings, the bonnet or the tailgate is cosmetic: not a rejection point, however unsightly. It gets serious when corrosion attacks the strength of the structure — the parts that must hold the car together in a crash and to which the wheels, seat belts and suspension are attached.
Where the inspector looks
- Floor pan — especially around the sills and under the driver's and passengers' feet.
- Chassis rails — the lengthwise "beams" of the car; corrosion here weighs heaviest.
- Suspension mounting points — strut towers, control arm and trailing arm mounts.
- Seat belt anchorages — the bolt points of the safety belts.
- Brake lines — strictly speaking not bodywork, but corroded lines are a classic rejection point found in the same check.
The inspector examines these zones and tests suspicious spots — rusted-through panels sound and feel different from healthy steel. Bubbling paint on a load-bearing part is almost always bad news.
What you can spot yourself
Without a lift you can't see everything, but three signs anyone can check: rust bubbles at the bottom of the sills, a damp or rusty floor under the interior mats, and rust traces or flakes on the spot where the car is parked overnight. In doubt? During an APK preparation the car is on the lift and we see it at a glance.
How the repair works
Structural corrosion is repaired by welding: the affected section is cut out and new steel is welded in, in a way that meets the inspection requirements — no filler, no patch glued over the top. After welding we treat the zone against new rust. Smaller repairs are often done within a day; bigger jobs we plan in advance with a clear quote, so you can decide whether the repair makes sense relative to the car's value. We give that advice honestly — including when the conclusion is that welding is no longer worth it.
Prevention: cheaper than welding
- Rinse road salt off the underside regularly in winter, especially inside the wheel arches.
- Keep the drain holes in doors and sills clear so water can escape.
- Have damaged underbody protection repaired before moisture creeps underneath.
- For a car you plan to keep long, consider rust-proofing the vulnerable zones.
Frequently asked questions
My car has rust on the doors. Will it fail on that?
No — rust on non-load-bearing parts such as doors is cosmetic and not a rejection point. Sharp edges from rusted-through panels can be an issue though, so have ragged rust edges assessed.
The report says "corrosion, load-bearing parts". What now?
Then welding is needed before the re-inspection. Send us the report — we assess the extent on the lift and quote before we start. The full process after a failure is in the step-by-step plan. We do not carry out the inspection itself; that happens at an RDW-approved centre.
Is an older car with some rust still worth saving?
Usually yes. What matters is where the rust sits and how far it has progressed. We will tell you honestly when a repair makes sense and when it doesn't.
Failed on this point? See APK preparation and repair in Tilburg.