A door built for a house from the 1938-1981 window was almost never designed with an insulated core, because insulation wasn't the standard it is now and this is a severe cold climate that punishes an uninsulated slab. Steel skins with no foam backing contract and flex hard in a hard freeze, and over enough winters the panels warp at the seams or the bottom section cracks where road salt and snowmelt sit against it. That's the failure we see most in the 22 named areas that make up this service area's older neighborhoods - not one dramatic breakdown, but slow warping and seal failure that finally makes the door worth replacing rather than patching again. With 35,694 owner-occupied houses in the service area and a median household income of $62,149, most owners we talk to are weighing a full replacement against another repair, and for a door already past 40 years old with an uninsulated slab, replacement usually wins on the math once you account for a repair man's second visit.