A door built into a house from the mid-1990s is not failing for the same reason a 1972 door fails. The 1990s builder-grade door - usually a plain steel panel, minimal insulation, a stock torsion spring sized for a lighter weight door - is now roughly 30 years old. That's past the working life of the spring and the rollers even if the door itself still looks fine from the driveway. The failure here isn't structural, it's mechanical fatigue: springs that have cycled tens of thousands of times, openers original to the house reaching the end of their gear life, and steel that's thinner than what's sold today. In the colder stretches of a Missouri winter, that older steel also flexes and binds more at the seams than a modern insulated panel would. We're not replacing doors here because the house shifted or the opening was never right - we're replacing them because 30-year-old hardware runs out.