How to Make a Concrete Ramp Over Existing Stairs
You may need to build a concrete ramp into your home to provide access to someone confined to a wheelchair, pushing a stroller, or someone who for another reason can not walk up stairs. A concrete ramp will also provide a sturdy base that can be used to transport heavy equipment in and out of a building. Fortunately, getting one of these outside your home is not hard. You can easily do this project on your own.
ADA Guidelines and Building Codes
Building a concrete ramp over the existing concrete stairs can be done, though you must follow some guidelines to comply with the American Disability Act. For example, a concrete ramp can not exceed a slope of more than one inch for every 12 inches of rise. Be sure to familiarize yourself with these guidelines as well as any local building codes before you begin.
Step 1 - Measure and Frame
Check out the height of the existing stairs. If it's more than 12 inches, you will need to pour a landing at the top. Chances are, however, that there is already some form of landing before entering the home, so this may need to be modified accordingly.
Following the grade of the stairs, and following rule of the one inch per 12 inches of rise, make a frame with plywood. Cut the tops with the circular saw to keep with the grade and rise. Pound in the 2x4s at regular intervals along the back of the plywood to keep it secure.
Step 2 - Prepare Area for Concrete
First, remove any sod or grass that is in your workspace, such as at the bottom. Dig a few inches deeper at the end of the ramp as well so the concrete can be thicker at this point.
Thread concrete ties under the plywood to the other side next. Nailing these to the side will give the walls some added strength when the concrete is poured. Depending on high you are going, there will be tremendous pressure on the plywood, so if you need to, double up on the ties.
Finally, drill holes into the existing steps. To bond the stairs and ramp together, place rebar in these holes so they stick into what will be the concrete of the ramp.
Step 3 - Pour
Pour the concrete, packing it in as you go. Begin screeding the concrete as it pours as well to keep it at the level of the plywood tops. Tap the sides of the plywood walls with the mallet to fill in any pockets.
If your rise is above 12 inches, you may want to use concrete dividers every few feet to keep the concrete from sliding down the ramp and out the bottom. These will keep everything contained in a particular section. Then, continue screeding until the concrete is level and smooth. Run the broom over the surface to give the surface texture that wheelchair wheels can grip on to.
Step 4 - Finish
Allow the concrete to properly cure for a few days, and then remove the plywood forms. At this point, you may need to add side walls to the ramp using small six-inch lips, added to either side. Alternatively, you can add a railing system using concrete screws and either metal or wood railings.