Opening Force [§404.2.9]
The maximum 5 lbf opening force applies to all accessible doors and gates except:
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fire doors (minimum opening force allowed by code)
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exterior hinged doors (no maximum specified)
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latch bolts and other devices that keep doors or gates closed
The 5 lbf maximum applies to the continuous application of force necessary to fully open a door, not the initial force needed to overcome the door’s seal resulting from unequal pressure. Latch bolts must be retracted and other devices that keep doors or gates closed must be disengaged prior to measuring the opening force. (Such devices, like other door and gate hardware, must operate with a maximum 5 lbf force (§404.2.7), but their operating force is not included in the measure of door or gate opening force). Door pressure gauges and other products are available to measure the opening force.
Measuring Door or Gate Opening Force with Pressure Gauge
When using door gauges and other measuring devices, it is advisable to follow these steps (except where product instructions specify otherwise):
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Open the door so that the face edge aligns with the door frame outside edge
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Place gauge immediately above door operating hardware about 2½” from the latch edge of the door (approximately the centerline of the door hardware)
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Push slowly keeping the pressure gauge perpendicular to the face of the door
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Remove the pressure gauge when the door is open 70 degrees.
Opening Force of Exterior Doors
The opening force of exterior swing doors is impacted by wind loading and other exterior conditions, gasketing, HVAC systems, energy efficiency, and the weight of doors. The minimum force needed to ensure proper closure and positive latch usually exceeds the accessible limit of 5 pounds of force (lbf) required at other doors. For this reason, a maximum opening force is not specified for exterior hinged doors.
Recommendation: Automation of exterior doors is recommended, especially where the opening force is likely to be significant. Otherwise, closers should be calibrated with the least force necessary for closure to minimize the opening force. Difficulty opening manual entrance doors is a common access complaint.
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