How to Build a Wheelchair Ramp Over Two Steps

Lay two 1 1/2-by-3 1/2-by-90 inch treated boards parallel to each other on the working surface with their largest surfaces facing down. Move them about 4 feet apart. Set a 3/4-by-48-by-96 inch treated sheet of plywood on top of these long boards and adjust the long boards so that their outside edges are even with the outside edge of the plywood sheet.

Drill holes every 12 inches into the plywood sheet and through to the long boards. Attach the long boards to the plywood by placing galvanized 2-inch wood screws in the holes and tightening them securely.

Set four 1 1/2-by-3 1/2-by-41 inch treated boards perpendicular to the long boards and evenly spaced between them. Drill holes down through the plywood sheet and into these boards every 10 inches. Attach them to the plywood sheet with 2-inch galvanized screws placed in the holes and tightly fastened.

Position a 1 1/2-by-3 1/2-by-48 inch treated board against one end of the long boards. Make it perpendicular to them with its largest surface flush against the end of the long boards and its long, thin surface against the plywood. Attach it to the plywood by drilling eight holes through the plywood and into this horizontal board, which is the stair attachment board. Set 3-inch galvanized screws in the holes and tighten them securely.

Place the stair attachment board up against the front face of the top step so that the plywood hangs on top of the top step. Drill six holes through the stair attachment board and into the front face of the top step. Secure it in place with 3-inch galvanized screws.

Set a 1/4-by-6-by-48-inch strip of rubber across the crack between the plywood and the top step surface. Staple it in place on the plywood and the top step, placing the galvanized staples every 6 inches to prevent bubbling and tripping.