How to Replace My Stairs With a Ramp

Ensure the landing at the top of the staircase is large enough. According to the Americans with Disabilities Act, a landing should measure at least 36 inches wide and 60 inches long so individuals in wheelchairs have enough space to turn around in a chair. If the porch or landing at the top of the stairs is not big enough, you can extend it with 2-inch thick deck boards as you build the ramp.

Calculate the length of the ramp. The maximum slope of a ramp should be no more than 1-to-12, meaning there should be at least 12 feet of run for every foot of rise. The run refers to the length and the rise refers to the height. If the top of the stairs, for example is 3 feet off the ground, the ramp needs to be at least 36 feet long.

Determine the best configuration for the ramp. If you do not have enough space to make a straight ramp, you can make one that is U- or L-shaped. However, you must also build a level platform at each bend in the shape so a user can rest. A switchback ramp has two parallel ramps that differ in height and a platform at the top of the first ramp.

Attach 4-by-4 deck posts to 3/4-inch-thick plywood bearing plates measuring 12-inches square. You should center one plate to the bottom of each post you use. Use deck screws to attach the plates to the posts, with a screw at each corner. You need a post along the ramp every 5 feet. If you want to create a permanent ramp, set the posts in concrete instead of on plates.

Secure diagonal 2-by-4 braces and 2-by-6 cross supports to the posts with joist hangers and deck screws for every 21 inches of height between the bottom of the post and the ramp.

Outline the shape of the bottom landing using 1-by-6 boards, which serve as runners. Secure the lumber together with nails and set the runners in the ground so they are flush with the sidewalk. You made need to use a shovel to dig out dirt that is in the way so you can set the runners into the ground. The shape that you make with the runners depends on the shape of the landing you want to make. Bear in mind that the landing should be at least 60 inches long and 36 inches wide. When the bottom of the ramp is a concrete pad, driveway or sidewalk, you may not need to create a landing at the bottom of the ramp.

Construct the ramp frame out of 2-by-6 lumber, using the runners as a size guide. You will need a frame for each stretch of ramp and each platform. The head and foot boards of each ramp frame should equal the width of the ramp. The boards on the size of frame should measure the length of the ramp. You may need to use more than one length of lumber for the sides of the frame, depending on the ramp's length. Secure the lumber for the head and foot of the frame to the boards for the side of the frame with deck screws. Then add 2-by-6 cross supports that measure the width of the ramp every 16 inches on center. Use deck screws to secure the cross supports to the frame.

Attach 12-inch steel corner gussets along the posts and secure them with 1/2-inch carriage bolts. This type of gusset has a pentagonal shape with short lower sides. Since the gusset will help hold the ramp frame in place, so you should install them at the heights and slopes you calculated for the ramp's slopes. When you place a gusset on the post, line up one of the long edges of the gusset along the side of the post that faces the ramp landing or platform so the edges are flush. To help make determining the placement of the gussets simpler, have a partner hold a long board along the inside of the ramp posts at the height and incline you calculated. Mark where the bottom of the board meets each post. This mark represents the location of the top perpendicular edge of the gusset.

Attach a 2-by-6 cross member to the posts, between each gusset. Use joist hangers and deck screws to secure the lumber. For additional support, use carriage bolts to secure the cross members to the installed gussets. Place the carriage bolts in the gusset pilot holes that the joist hangers do not cover.

Place the deck frame onto the gussets, securing them with carriage bolts.

Lay 2-inch-thick deck boards over the ramp frame and secure them with deck screws.

Add handrails if the ramp is more than 6 inches off the ground. Handrails should have a rounded shape and be between 2 1/2 inches and 1 1/2 inches in diameter. If the handrail is for a wheelchair user, a good height for it is 24 inches.