One of the most common and costly mistakes when ordering a steel roll up door is measuring the opening incorrectly. A door that's even a few inches off in width or height won't fit properly — and returning or exchanging large commercial doors is expensive and time-consuming. Here's how to measure correctly the first time.
Measuring the Rough Opening Width
The rough opening is the structural opening in your wall — the clear distance between the framing members on each side. Measure the rough opening width at the bottom, middle, and top of the opening, and use the smallest measurement. This accounts for any framing that isn't perfectly plumb. For a standard roll up door, the door width you order should match the rough opening width — the door's guides mount inside the opening on each side, so no additional clearance is needed in the width dimension. Always confirm this with your door supplier, as guide configurations can vary by manufacturer.
Measuring the Rough Opening Height
Measure the rough opening height from the finished floor to the underside of the header (the structural member across the top of the opening). As with width, take three measurements — near the left jamb, center, and right jamb — and use the smallest. For roll up doors, you also need to measure the available headroom above the rough opening header to the ceiling or next obstruction. Roll up door assemblies require clearance above the opening to house the coiling drum and curtain. Duro Doors can help you confirm whether your headroom is adequate for the door model you're considering.
Side Room, Back Clearance, and Other Considerations
In addition to rough opening dimensions, roll up door installation requires adequate side room — the distance from the opening's edge to the nearest wall or obstruction — for the guide tracks. Most standard commercial roll up doors require 6 to 8 inches of side room on each side. Back clearance, the depth available behind the opening for the door operator (if motorized), is also a factor. Before ordering from Duro Doors, have all five measurements ready: rough opening width, rough opening height, headroom, side room (left and right), and back clearance.
Not sure about your measurements? The Duro Doors team is happy to help. Call us before you order to make sure you get the right door the first time.