Perforation
Rust that eats all the way through a panel — the threshold most corrosion warranties require before they will pay for anything.
Part of the Coverage types cluster.
What it means
Perforation means a hole caused by corrosion, typically from the inside out. Most corrosion warranties cover only perforated panels, which is why surface bubbling rarely qualifies: the standard is a hole through the metal, not a blemish in the paint.
Why it matters
Knowing the standard prevents arguments at the shop. Photograph the rust, and establish whether the panel has actually perforated before filing a corrosion claim — it changes the conversation entirely.
What it is NOT
It is not surface rust, not paint damage, not rust caused by stone chips or accident repair, and not a defect the basic warranty covers.
Related terms
Terms in this glossary describe general warranty practice and US norms — they are informational, not legal advice, and not a reading of your specific warranty booklet.