Dock and overhead doors for warehouses and distribution centres
In a warehouse or distribution centre the door is part of the throughput: a dock door can cycle hourly around the clock, a bay with a working door and a broken leveller is still a bay that is down, and the forklift that hits a guide stops a lane until it is fixed. Commercial Garage Doorman services the whole opening, door and dock equipment, in one visit, for warehousing, 3PL and distribution sites along the QEW and 401 from Hamilton to Niagara.
By Commercial Garage Doorman, Grimsby, Ontario · Updated
What makes a dock door different from any other overhead door?
Duty and danger. DASMA’s sheet on dock doors notes duty cycles that can run hourly, around the clock, a dock floor about 48 inches above grade to meet trailer beds, and the operating rule that a dock door should not be opened unless a transport vehicle is parked at the dock, because an open door on an empty dock is a four-foot drop to concrete. Springs, operators and safety devices on these doors have to be rated for that use, not for a door that opens twice a day.
Source: DASMA Technical Data Sheet #182, Technical Considerations for Dock Doors (PDF). Checked 23 October 2026.The door is only half the bay. Levellers, seals, shelters and bumpers fail on their own schedule; our dock equipment service covers them on the same visit as the door, and the dock door guide covers sizing and wind ratings.
Should a busy interior or dock opening get a high-speed door?
It depends on the count. DASMA’s energy analysis compares a high-speed door with a conventionally operating insulated sectional door and finds the annual energy use equal at 20,000 cycles a year, about 55 a day; at 75 cycles a day the high-speed door saves about 10%. The reason is air exchange: an open opening typically moves air at about 3 feet per second, and a door that opens at 32 inches a second, closes at 24 and recloses automatically keeps that time short.
| Daily cycles at the opening | Lower annual energy use |
|---|---|
| Under about 55 | Insulated sectional door |
| About 55 (20,000 a year) | Equal: the crossover |
| 75 or more | High-speed door, about 10% savings at 75 |
More on the trade-off, including headroom and security, is in high-speed door or rolling steel.
How do you stop forklifts taking out the guides?
With steel in front of the door rather than behind it. DASMA’s recommendations, written for rolling steel fire doors where damage can stop the door closing in a fire, apply to any busy forklift opening: guard posts such as concrete-filled steel pipe rigidly fixed to the floor in front of each guide, a heavy steel horizontal guard several feet in front of the opening with its bottom slightly below the top of the opening so a raised mast hits the guard first, and face-mounted guides where possible, because guides between the jambs narrow the opening and get hit more.
Source: DASMA Technical Data Sheet #290, Protecting Rolling Steel Fire Doors from Vehicular Traffic Related Damage (PDF). Checked 23 October 2026.A door that has been hit should be inspected by a trained door technician, which is DASMA’s advice too. A bent guide on a rolling steel door binds the curtain; a cracked section on a sectional door can let it come off the track.
How often should a distribution centre’s doors be inspected?
More often than the minimum, because the minimum is written for ordinary use. The industry floors are an annual inspection of each rolling door by a trained technician, a quarterly performance check on powered doors, and monthly checks of sensing edges and photo eyes A site running docks around the clock has every reason to go past those floors, and how far is a decision for the door count and the duty. Our planned maintenance program is $60 per door a year plus HST and keeps a per-door service log for every bay; the full breakdown with each source is on how often a commercial door should be inspected.