ADA Ramp Specifications
As defined by the ADA, a ramp is a sloping route constructed with a slope greater than 1:20 (1 inch of vertical rise for every 20 inches of horizontal length, or run) and must conform to the standard ADA specifications for ramps.
Ramps may have a maximum slope of 1:12.*
Ramps must be a minimum of 36 inches wide. Some areas require wider ramps.
All edges must be protected to keep anyone from slipping off.
All ramps shall have top and bottom landings as wide as the ramp itself and at least 60 inches long.
Landing size must be at least 5 feet square.
Ramps must have handrails on both sides if their rise is greater than 6 inches or their length is greater than 72 inches.
Cross slopes (areas where a ramp slopes sideways, perpendicular to the ramp's length) must be less than 1:50, and surfaces must be slip-resistant and stable.
A level landing is required at the bottom and top of the ramp.
Maximum threshold height (at building entry) is 3/4 inch (19 mm) for exterior sliding doors and 1/2 inch (13 mm) for other types of doors without modification.
[* Recommended Ramp Slope
While the maximum slope allowed by ADA guidelines is 1:12, the ADA recommends a more gradual slope of 1:16 to 1:20, whenever possible. A 1:12 ratio is too steep for some people to navigate, and a lower slope may be required for some public buildings. Depending on the slope and the material used to build the ramp, the surface may need some extra anti-slip texture to help prevent slipping.]
