- 1). Measure the height of your ramp using a straight edge. For example, if your ramp will climb two steps, measure the height of both steps in inches.
- 2). Measure, in inches, the ground length of the ramp. Measure flat on the ground, where the step begins, to the point where your ramp will end.
- 3). Use the Pythagorean theorem to find the length of your ramp.
If your ramp is 16 inches high and 192 inches long, the Pythagorean theorem is 16^2+192^2=ramp^2. 16^2+192^2=37,120.
37,120 is equal to the square of the ramp, so calculate the square root of 37,120. sqrt(37,120)=192.66 inches, or almost 16 feet. - 4). Check your local building code for how much drop is allowed in your ramp. A rule of thumb is a drop of no more than 1 inch in height for each foot of length. Proceed if your ramp is the correct length.
- 5). Cut the 2x12 pressure-treated pine boards to fit the length of your ramp. Place the board on its side where the ramp is going to be. Snap a chalk line from the top to the bottom of the ramp. Rip with a circular saw.
- 6). Cut 2x6 supports every 16 inches of length. Attach between the 2x12 boards to make a "ladder." Notch the top of the boards where they meet the steps.
- 7). Screw the plywood to the 2x12 boards.
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