How to Cut a Ramp for Stairs

Determine the length of the ramp by measuring the vertical distance from the bottom of the stairs to the top of the stairs, using a measuring tape. To suit ADA standards, the ramp should be 12 feet long for every 1 foot of vertical rise.

Cut sections of 2-by-6-inch pressure-treated lumber with a circular saw to form the stringers, which are the long sections that support the ramp from the bottom to the top of the stairs. You need a stringer for both sides of the ramp, plus an additional stringer for the center. If the ramp is longer than 12 feet, you need to bracket and bolt the lumber sections to complete each stringer.

Cut the ends of the stringers at 8.33 degree angles with a miter saw. This allows the stringers to sit flush with the floor or ground, as well as with the floor or deck joist at the top of the stairs.

Determine the width of the ramp. The Americans with Disabilities Act specifies that ramps should have an unobstructed width of at least 36 inches. Cut 1-inch decking boards to the width of the ramp. You need enough decking boards to cover the ramp when attached perpendicular to the stringers.

Measure the distance between the floor or ground and the bottom of the stringers at 12-foot intervals. Cut sections of 2-by-6-inch pressure-treated lumber to these measurements with a circular saw. These sections form the support posts for the stringers -- you will need one support for each 12-foot length of each stringer. Miter one end of each support post at an 8.33 degree angle with a miter saw.