With proper care, regular inspections, and good maintenance, roll-up doors on a semi-trailer can last at least 8-10 years. However, if exposed to harsh environments or heavy use, their lifespan may be shorter. Neglecting regular maintenance further reduces their longevity. In poorly maintained cases, you might expect a lifespan of 4-8 years, but with consistent upkeep, the door can endure for decades alongside the trailer.