Things You'll Need
2x4 or 2x6 wood
1x6 wood planks
If the ramp is going to be more then 30 inches at the highest point, you will need a guardrail. It is suggested you create a curb around the ramp if it is not going to be next to a wall. This is so the wheelchair will not fall of the ramp. This can be created at the same time the ramp is being formed and poured. Ramps that are longer the 30 feet need an intermediate landing. Create a landing area at the top and the bottom of the ramp. Make sure there's room to open the door at the entry. If you are pouring a lot of concrete, it's best to get a concrete truck and pumper.
Concrete work requires a lot of heavy lifting.
Buy more than enough concrete. It is better to overestimate than run short and not be able to finish. Concrete needs to be poured all at the same time or there will be cracks between the two pours.
Wheelchair accessibility is a big issue for many people. Since the 1990s, the Americans with Disabilities Act has made it law for public facilities to be accessible to those with disabilities. But many are also faced with having to retrofit their home entryways to accommodate a wheelchair or motorized scooter.
Measure the area where the ramp is to be located. An ADA ramp is required to be 36 inches wide and cannot exceed a 1:12 slope. For example, if you only need to go up 1 foot, then your ramp will be 12 feet long and 3 feet wide.
Mark the ramp area using stakes and string.
Measure how high you need to go to meet the entryway, and then calculate the length of the ramp using the 1:12 slope rule.
Creating the Forms
Cut the 2-by-4 or 2-by-6 wood and planks to create the form work that will hold the concrete in place. Dig deeper into the ground when placing the wood at the bottom of the ramp. The concrete needs something to stop it. You will also have something to screed the concrete with.
Place stakes around the form work to ensure it will hold the concrete.
Cut the top level of the form work to match the 1:12 slope. This way, you can use it as a guide when you screed the concrete level.
Place the rebar inside the form. Use 3/8-inch rebar spaced 6 inches apart to form a grid. Rebar will help to give the concrete the strength it needs and keep it from cracking too much.
It is best to overlap the rebar when making a longer ramp. Use wire to tie the rebar pieces together.
Pouring The Concrete
Mix the concrete according to the instructions. It should look like thick oatmeal.
Pour the concrete on the thickest part of the ramp first.
Pour evenly until the entire ramp is filled and concrete is all around the rebar.
Vibrate the concrete to ensure it gets in all the small spaces and eliminates any air bubbles.
With a wooden screed the width of the ramp, smooth the concrete so it is level with the form work. The wooden screed will help distribute the concrete to places where there wasn't enough poured and move the concrete out of places where there was too much concrete poured.
Finishing the Ramp
Smooth the concrete with a steel trowel.
After the concrete has been troweled and before it has hardened too much, apply a broom finish. Take a medium-bristle broom and lightly sweep lines onto the concrete. This will create texture, helping to ensure people will not slip when it gets wet.
After the concrete has hardened, remove the form work.
You will need to wait until the concrete cures completely before you can use the ramp. Then spray the concrete with water to help it from drying up too quickly.
Carol Reeves is a licensed architect with more than 12 years of experience in architecture and construction. In 2003 she began writing and editing for local publications, as well as teaching at community colleges. Reeves holds a Bachelor of Architecture from California State Polytechnic University, Pomona.