For more than a decade, distribution centers and other commercial facilities have used impactable dock doors to minimize the damage and business interruption incurred by forklifts and other vehicles hitting these entryways. More recently, however, facilities professionals have discovered that some of these same systems can also help reduce the damage sustained by both the positive and negative wind-load pressures associated with hurricanes, tornadoes, or high wind gusts.
Since wind conditions vary based upon location, it's important that facilities professionals work with their architects and engineers to determine specific wind-load pressures for each facility. While manufacturers want to increase the strength of their products, they also realize that doors need to remain as lightweight as possible for ease in opening.
Once you've conferred with your architect and local code consultant to determine the specific wind-load requirements for your building's location, Wayne Straus, general manager at TKO Dock Doors (based in Sussex, WI), suggests that you ask the following questions of your potential suppliers:
- What type of door do you have that will meet building-code requirements for this facility?
- How long will this door last with the material-handling conditions I have at this facility?
- How will this door seal out the elements at this facility?
- How can you reduce my total cost of ownership with this door?
One key attribute of one design of modern-day dock doors, referred to as "knockout doors," is the ability to "release" upon substantial impact, reducing downtime at the loading dock. The sections on knockout doors each feature a spring-loaded plunger that rides in the groove of a beveled track system. Upon impact, the pressure is transferred to the plunger, allowing an individual panel or multiple panels on the door to release into the opening. Afterwards, the door or section can simply be pulled back into the track and reset within a few seconds.
Gary Brooks, assistant general manager for an 800,000-square-foot direct delivery center for Sears in Jacksonville, FL, finds this "breakaway" feature to be a great advantage for the 114 shipping and receiving standard openings at his facility. "If a truck or major force collided with one of these doors, we would want it to give first rather than incurring major damage to the building structure," he says. With proper maintenance, Brooks expects these doors to last well beyond the life of his 10-year lease. It was also important that the systems selected could be easily inspected and adjusted by his in-house maintenance department.
At least monthly, Straus suggests that building professionals conduct a door inspection and do routine maintenance. "Visually check the track, the panels, the springs, cables, rollers, hinges, pulleys, brackets, and other hardware for damage," he explains. "Doors can be very dangerous if they're not maintained properly; the springs can be loaded with 400 or 500 pounds of pressure. When visible damage is found, don't hesitate to address those concerns immediately with a certified technician."
Linda K. Monroe ([email protected]) is editorial director at Buildings magazine.