Rolling steel door repair in Detroit, MI.

A typical rolling steel door repair in Detroit costs $350 to $1,200 per door. That covers work like replacing damaged slats, a bottom bar or astragal, or resetting a curtain that came out of its guides. Spring replacement runs $650 to $1,600 per barrel, and a new operator runs $1,400 to $3,200.

The price follows the parts and the access. A 10-by-10 door on a dock with clear floor space is a different job from a 16-foot door over a production line where a lift has to be brought in and the line stopped. Slats come in different profiles and gauges, so a door with flat slats from one maker may need parts ordered, while common curved slats are easier to find. The bottom bar takes the most abuse because pallet jacks and forklifts hit it, and the rubber astragal under it splits after a few Michigan winters. If the door is old enough that the maker is gone, replacement slats can still be matched by profile and gauge. Send a photo of the label on the coil hood or the guide, if there is one, and the quote gets tighter.

A door that stops partway or hangs lower on one side usually has a broken torsion spring, a slat pulled out of its guide, or a bent guide. Trucks and forklifts cause most of it. A worn operator brake or a slipped limit setting can also stop a motorized door short.

The curtain rides in two steel guides bolted to the wall, and its end locks keep the slats lined up. When a forklift mast catches the curtain or a truck backs into a guide, the slats twist and the end locks pop out. The door then binds every time it reaches that spot. One side dropping lower than the other is a classic sign that a spring inside the barrel has let go, since the counterbalance is no longer even. On a motor-driven door, check whether the operator hums without moving, which points to the brake or the drive, or whether it simply stops at the wrong height, which points to the limit switches. None of this should be fixed by forcing the door. A bent curtain run through a straight guide gets worse with every cycle.

Replace the springs when one breaks, when the door feels much heavier to lift by hand or chain, or when the door will not stay put halfway. Springs are rated in cycles, one open and one close. A busy dock door wears through standard springs far sooner than a door opened twice a day.

Rolling door springs sit inside the barrel above the opening and are wound under tension, which is why this is not a job for building maintenance staff with a ladder and a wrench. When they are replaced, the technician releases the tension, swaps the springs, rewinds them to match the curtain weight and checks that the door balances. Standard springs are commonly rated around 20,000 cycles, and high-cycle springs are available for doors that run all day. Count how many times your busiest door cycles in a shift and say so on the call, because a door that opens 60 times a day may be worth the high-cycle option. Rust on the spring coils, a gap in a coil or a loud bang from the hood are signs the next failure is close.

If the door opens many times a day or staff struggle with the chain, a motor operator usually pays for itself in time and injuries avoided. Operators run $1,400 to $3,200 installed. The door has to be balanced and in good shape first, or the motor wears out fast.

There are three common ways to drive a rolling door: a hood-mounted operator that sits on the bracket and drives the barrel, a wall-mounted jackshaft operator connected by a chain, and the manual chain hoist most older Detroit doors still have. Operators come with a push-button station, and many add photo eyes or an edge sensor on the bottom bar so the door reverses if something is under it. Ask about a sensing edge if forklifts or people pass under the door during shifts. Check the power supply as well. Many industrial operators run on three-phase power, and older buildings may only have single-phase at the door. Have someone check the panel or tell the call taker what voltage is available, and whether a fire door is involved, because rolling fire doors need operators listed for that use.

Rolling fire doors get a drop test at least once a year under NFPA 80, which proves the door closes by itself when the alarm or fusible link releases it. The door is then reset and the test is written up. Doors that fail the drop test need repair before the next inspection.

A rolling fire door stays open in daily use and is held by a release device. In older doors that device is a fusible link that melts in heat, commonly rated at 165 degrees. Newer doors are tied to the fire alarm and close when it trips. The governor in the hood controls the speed so the door does not slam down at full weight. During the test the technician releases the door, watches it close fully and latch at the floor, measures whether the speed looks right and then resets the release mechanism. Common failures are a door that stops partway, a governor that lets it fall too fast, or a release device that has been painted over or wired open. Fire marshals in Detroit and the suburbs ask for the written record, so keep it with the building's fire safety papers.

Repair it when the damage is limited to a few slats, the bottom bar or one guide, and replace it when much of the curtain is bent or rusted through. A new installed rolling steel door typically runs $3,500 to $9,500, so a slat repair is usually the cheaper first step.

Slats are replaced in sections, so a door hit once at forklift height can often be fixed by swapping the damaged slats and straightening the guide. The math changes when the curtain has been hit many times, the barrel is bent, the springs are tired and the operator is from another era. At that point replacing everything at once can cost less than three separate repairs over two years. Door size, steel gauge, insulated slats and the operator move the price of a new door the most. Insulated slats help heated warehouses and food buildings hold heat in a Detroit January. If the opening is fire-rated, the replacement has to be a labeled fire door, which costs more than a standard service door of the same size.