How to Lay Out a Handicap Ramp

Locate the entry-way for which the ramp will function as wheelchair access. Ideally, build the ramp away from trees and shrubs so that debris is less likely to obstruct the ramp. Avoid shade from structures, as more exposure to sunlight will lessen the likelihood that mold, mildew or moss will grow on the ramp, and the sun will aid in melting snow or drying moisture.

Decide on one of three choices for ramp configuration. A "straight shot" design has landings and ramp in a straight line. An "L-shape" changes direction at a 90-degree angle. A "switchback" changes direction at 180-degree angles between one ramp, a landing and another ramp in the opposite direction. ADA guidelines require a landing placed at each point where a ramp rises 30 inches per 30 feet of ramp.

Measure from the ground to the landing at the point of entry to determine how much rise is needed from the lowest point at the beginning of the ramp. If a section of ramp rises 30 inches in 30 feet, a landing must be provided. No section of ramp may rise more than 1 inch in every 12 inches, according to ADA requirements.

Specify a minimum of 36 inches ramp width to meet the ADA rule, but a width of 40 inches is recommended for better clearance. Landings must be 5 feet long. For an L-shaped turn, landing width must be 5 feet, for a switchback turn 8 feet. Landings must be level to assure that a wheelchair will not tip on a slope. Design for door clearance on the ramp at building entryway.

Provide walls and handrails on both sides for ramps with rises over 6 inches high or more than 6 feet in length. Handrails must be parallel to the floor, and extend 12 inches beyond top and bottom of the ramp. The ends must be extended to the wall, floor or post, or rounded at the ends. Clearance between the wall and the handrail should be 1 - 1/2 inches. The top of the handrail must be between 34 and 38 inches from the ramp floor.