A properly constructed ramp gives a disabled person access to and from a residence or a business. When you’re building a wheelchair ramp, there are minimum specifications that you must satisfy. There are three main categories of wheelchair ramps; bermed ramps where the ground level is raised, formed and poured; concrete ramps; and the most common, post ramps, constructed of wood planking on secured in-ground posts.
Determine which type of ramp is best suited to your project. Bermed ramps are only feasible in places where the soil does not come into contact with wood. This is a popular method when landscaping a commercial business and it is an important part of the overall design. A bermed ramp may look like a sidewalk following a gently-sloped path.
Choose concrete if the ramp will get a lot of wheelchair traffic. This type of ramp is advisable in a business district. However, most homeowners choose a post ramp, where support posts, set in the ground with concrete, offer a sturdy base on which to build the wheelchair ramp.
Check with your local building inspector to find out if you need a permit and ask for a copy of the building code for wheelchair ramps. Most communities use the Americans with Disabilities Act (ADA) code. Even if your community does not require additional regulations, the ADA codes are in effect and you can view them online (see Resources).
Plan the slope of your ramp, not to exceed a 1:12 slope. This means that for every 12 linear inches of ramp, it must not rise more than 1 inch. For instance, if you need a ramp that extends from the ground to the top, at a height of 2 feet, you would multiply the height in inches (24 times 12) and come up with 288 inches. That equals 24 feet, so you would plan a minimum of 24 feet from the beginning of your ramp to the entrance.
Allow a width of at least 36 inches for your ramp. This is free room, so any deck trim or handrails must not be included in this measurement. In addition, a ramp must have a minimum run of 30 inches. This means that all ramps must be at least 30 inches long. This is an issue if you need only a small ramp with a rise of less than 3 inches high. This provides stabilization in small rises.
Build handrails on any ramp with a rise of more than 6 inches. Install handrails at height of 36 inches and make sure they are continuous on both sides of the ramp. Handrails must be secure and provide at least a 1 ½-inch space between the rail and a wall.
Provide a landing at the top and the bottom of your ramp that is at least 60 inches long. This enables a wheelchair user to rest safely on a level surface. In addition, all landings where a ramp switches directions must have a level floor area of 60 inches in all directions.
Drive concrete support posts into the ground if you are using the post method of construction and countersink all screws in the decking. Seal all wood decking to prevent weather-related warping.
Although the minimum slope for a ramp is 1:12, a more comfortable slope is around 1:18. If a disabled person will be manually wheeling himself up the ramp, use a gentle grade. 1:12 is fine for motorized wheelchairs and scooters.