The Americans with Disabilities Act (ADA) is important legislation that acknowledges the civil rights of individuals with differing mobility. Although the ADA is not a law, almost all of the contemporary building codes prescribe the Act's requirements. Acceptance of the ADA's specifications is required across most of the country.
A ramp is any inclined plane that has a slope greater than 1 inch rise in 20 inches of run. The maximum slope a ramp can have is 1 inch of rise in 12 inches of run. Ramps with slopes greater than 1:12 are considered inaccessible and will not pass inspection.
All ramps greater than 1:20 must have a 5-by-5 foot landing after 30 inches of rise. So, a 1:12 slope will have a landing every 30 feet. A ramp with a slope between 1:16 and 1:20 will have a landing at least every 40 feet.
Ramp Direction Changes
Ramps that change direction or switch back must have a landing at the junction between the two legs of the direction change. This landing must measure 5 by 5 feet. If there is a door at any landing, the door must have a clearance of 48 to 54 inches, including an 18- to 24-inch side manoeuvring space at the door's swing.
Ramp Handrails and Guardrails
Handrails must be continuous along the ramp and landings. The handrails must be 34 to 38 inches in height, extend no more than 3 inches into the ramp space and be no more than 1 1/2 inches in diameter. Also, the handrail must extend 1 foot into space at the ends of the ramp.
The surface of the ramp cannot have variations or protrusions greater than 1/4 inch. If there are surface protrusions up to 1/2 inch in height, a 1-inch rise to 2-inch run bevel can be placed on the protrusion edges to create an acceptable transition. Carpet can have a pile thickness no greater than 1/2 inch, and gratings must be no greater than 1/2 inch in width.