• Ramps should have a maximum slope ratio of 1:12, which means 12 feet of ramp per each foot of elevation.
• A level area must be located at the top and bottom of a ramp. If a porch is not present at the top, a platform should be placed over the steps in front of the door. No run over 30 feet is allowed without an intermediate resting platform. This platform may be a straight or turn platform.
• If there is not enough area to install a staight ramp, it may be necessary to build cross runs from side to side.
• Any platform that changes direction must be at least 60" x 60" for wheelchair maneuverability. Ramps should be at least 36-inches wide, but a 44-inch to 48-inch width is recommended when installing handrails on the inside of a ramp.
• If a ramp has a rise greater than six inches or a horizontal projection greater than 72 inches, it should have handrails on both sides.
• The top of the handrail should be mounted between 30 and 34 inches above the ramp.

Building ramps makes areas accessible to people who have trouble using stairs or who use walkers, personal scooters, or wheelchairs. Anyone pushing a baby carriage or shopping cart will also benefit from a ramp. Although the guidelines for residential ramps are not as stringent as those for public areas, many neighborhoods with covenants, codes and restrictions have specific rules about how and if ramps may be added to a residence. Remember that ramps should have non-skid surfaces and be constructed so water cannot accumulate on walking surfaces.

With wooden ramps, boards may need replacing. Wooden ramps also may need to be repainted or have a nonskid material added to older ramps, and handrails may need to be secured. Metal handrails may need to be rewelded, rust removed and repainted, guard rails or pickets added. Although a 1:12 pitch (12 feet of ramp per each foot of elevation) is the maximum slope allowed, a gentler slope of 1:14 or 1:16 is preferable. One might decide to change the slope of a concrete ramp as the disabled person becomes older or weaker.

-- Tips courtesy of HomeAdvisor.com