What Is the Rise or Run for Installing a Handicapped Ramp?
The Americans with Disabilities Act Accessibility Guidelines for Buildings and Facilities (ADAAG) provides technical requirements for handicapped ramps. The rise and run for ramps can be calculated using ADAAG's slope guidelines.
Definition of Rise and Run
Any ramp or other sloped surface can be described in terms of rise and run. The rise is the vertical distance between a ramp's top and bottom, while the run is the horizontal distance from the ramp's start to end, measured perpendicular to the run.
Calculating Rise and Run
A ramp's slope is calculated by dividing the rise by the run---a formula commonly used to calculate the run required for needed rise. ADAAG sets the maximum slope for a handicapped ramp at 1:12, meaning that for 1 inch of rise, a minimum 12-inch run is required.
Additional Installation Planning Factors
When calculating the entire space that a handicapped ramp installation requires, it is important to note that ADAAG limits single continuous ramps to 30 inches maximum in height. Greater rise requires multiple ramps built with 60-inch minimum length landings between. ADAAG's guidelines hold additional clearance requirements for various ramp configurations.