ADAAG Manual

Door Opening Force [4.13.11]

Measuring Opening Force

The maximum force pertains to the continuous application of force necessary to fully open a door, not the initial force needed to overcome the inertia of the door. It does not apply to the force required to retract bolts or to disengage other devices used to keep the door in a closed position. In measuring with a push-pull scale, force should be applied gradually so that the applied force does not exceed the resistance of the door. While there are instruments specifically designed for this purpose (e.g., tensionometer), a device as simple as a spring-loaded plunger or "fish" scale is effective in measuring the force required to open a door.

Exterior/ Fire Doors

A maximum opening force is not specified for exterior swing doors because the closing force required by building codes usually exceeds an "accessible" resistance. Factors that affect closing force are the weight of the door, wind and other exterior conditions, gasketing, air pressure, HVAC systems, energy conservation, etc. Research sponsored by the Board ("Automated Doors" by Adaptive Environments Laboratory (1993) indicates that a force of 15 lb is probably the most practicable as a specified maximum. Considering that closing force is 60% efficient, a 15 Ib maximum for opening force provides 9 lb for closure and latching, which may be sufficient for most doors. However, a 15 Ib opening force greatly exceeds the 5 Ib maximum considered suitable for people with disabilities. Providing automatic door openers may be the only practical alternative for ensuring the usability of exterior doors in many cases. Otherwise, the closing force should be set to the lowest level possible. To avoid any conflict with building or life safety codes, ADAAG requires fire doors to have the minimum opening force permitted by the appropriate administrative authority.