How to build an eight foot long household wheelchair ramp

 

     When a relative had a stroke and suddenly became wheelchair-bound, access was needed for home care in three different family homes, including her own. I designed and built three simple wheelchair ramps. These ramps were made for access to homes with two step entries ranging from twelve to nearly eighteen inches high. There are two basic designs. Design one is eight feet long and covers steps up to 16 inches high.  Design two covers entrees up to 20 inches high. Here is a link to that 10 foot outdoor ramp. The longest ramp possible for the conditions is best. An eight foot ramp is easiest because plywood is readily available in four by eight foot sheets. A length greater than eight feet requires an additional length of plywood for the surface run. This post covers design one, the eight foot ramp. It is designed for occasional household use on a garage entry into a house. This project applies to conditions where the total rise of the ramp is 16 inches or less. These dimensions allow for the use of a 4 by 8 sheet of plywood for a final ramp pitch of 2:12 or two inches of rise for every foot of ramp. This is right at the maximum recommended pitch for a household ramp. If your entry point is any higher off the ground than that, a longer ramp will be needed. I have designed the ramp with the top resting on the first step and the lower end beveled to sit squarely on the floor. If used outdoors, pressure treated wood or painting would be recommended. The ramp was built over several weekends at a cost of under $40 and a weight of 58 pounds.

                                                       
                                                                    Overview                                     

• Safety: Safety glasses, gloves, hearing protection. 
• Tools: Wood saws (circular or table or hand or reciprocating), belt or other sander, electric drill, square or other straightedge, tape measure, angle finder (optional), clamps, saw horses.
•  Parts and materials: One 4 by 8 sheet of plywood (at least 3/8" thick), five 8 foot long 2x4s (good quality-I used fir), light thin material for side rails (such as scrap paneling), wood screws ( I used  2 1/2"   and 1" coarse thread drywall screws), poster board, spray paint. 
• Cost of materials: plywood $15.47, five 2 by 4s ($2.80ea) $14.00, screws $2.75. Total $32.22 Additional materials (I used existing leftovers) if purchased: carpet $10, rails $5. 
• Weight: 58 lbs.
•  Estimated time: 6-8 hours   

  1)      Cut the sheet of plywood to the width of the entryway threshold with a circular or table saw. Mine was 31 inches. This is a good time put a bevel under the leading edge of the ramp, at the ramp slope. 

  2)     Lay the cut plywood in place, propped up underneath as it will lie when the ramp is done. Now clamp the straightest edge of the straightest 2x4 along the eight foot length and an inch in from the edge. There are several approaches to use to duplicate the angle of the ramp with the ground.  One is to find the pitch of the ramp with a pitch and angle finder and then mark the runners to that angle using a protractor. Using an angle finder, I found my ramp to be at 10 degrees. Another is to make a template of the exact angle. I tried both and found the template to be a more reliable method. 

  3)    Method 1: Find the angle. We need to cut the lower supporting end of the 2x4 at 10 degrees to match the pitch of the ramp. I attempted to do this using a protractor, making  a line at 10 degrees through the corner of the lower end of the ramp and the 2x4 runner. Though I took great care marking and cutting the runner, the result was too far off to use. I then decided to make a template and though this is a bit time consuming and tedious, the result was much better.

  4)    Method 2: Make an exact template for the angle of the runner. Get a piece of straight material for the pattern.  I used poster board. Spray the edge of the lower two feet of the ramp with dark spray paint and press the board against it. Cut along the painted lower line and you should have an exact duplicate of the angle of the ramp. Check the fit by placing the template under the ramp. If it fits, great, but if not, undercut it and fill in along the length with thinner strips of material, taped in place. This is what I had to do. A template can also be made by using hot melt glue and a scrap piece of squared plywood. Simply glue the plywood to the side of ramp surface. Then mark it underneath and remove. Cut at the line and transfer to the runners. That worked great for me on a second ramp I built.
   

Carefully make a template of the angle at the lower edge of the ramp

  5)    When the template fits fine, transfer it to a 2x4. I spray painted the line onto the 2x4.

  6)    Carefully cut on the line. I cut it by hand first with a rip saw, then a reciprocating saw. A fence is needed to keep the reciprocating or other saw on the line. This is precision work. 

  7)    Check the finished runner by clamping it under the plywood ramp surface and check that it is flush on the ground along it’s entire contact surface. I’m good.

This will do, we have good even contact with the floor

  8)  Using the good first runner as guide mark the other three and repeat the cut. Check them when done if desired. Mine needed a little touch up with a belt sander to achieve a flat contact surface with the garage floor. Important: save the short wedge pieces leftover from these cuts, as they will be used to make a  level upper support platform for under the top of the ramp.

  9)  Turn the plywood ramp surface upside down and align the runners. Take care to use a square at the lower ramp end and make sure the cut ends of the runners align with the lower load bearing edge of the ramp surface. Mark the underside of the plywood with each runner’s final position as well as number both the runner and the underside of the plywood where they go. Though I tried, my runners were not identical.  So make sure that the correct runner is properly positioned before screwing down.

  10)   Now turn the runners over and position them on the floor in their correct orientation.

  11)   Place the plywood on them in correct orientation. Align all the marks underneath.

  12)   Fasten the plywood to the runners one at a time and at opposite ends with 2 ½ “ coarse drywall screws. Check the alignment by lifting it up and checking the marks. Better here to pull out a screw or two to fix misalignment. Of course on the angled end of the runner a shorter screw will be used at a distance in where there is some meat in the runner. I put in 20 screws.

The ramp surface attached to the runners with wood screws

  13)   Use the leftover angled pieces (wedges) to level the underside of the upper ramp and support it. I used a belt sander to even out all four wedges. Cut a piece of plywood from the leftover material to the same width as the ramp and same length as the runners (31 by 10 inches)

  14)   Now lay the materials on the runners of the upside-down ramp. Orient them over each runner and carefully mark the position of the wedges on the small piece of plywood.

This is the underside view of the upper support piece. It's like a mini ramp.

  15)   Screw the leveling wedges to the plywood. I used two screws on each one.

  16)   This is a good time to bevel the lower edge of the plywood for ease of getting the wheelchair started up the ramp. I used a belt sander.

  17)   At this point decide what finished surface, if any, you want on the ramp. This is especially important to do now if carpeting is being used as it will affect the final position of the upper support wedge. I decided on indoor outdoor carpeting. I cut the piece to size, leaving an overlap of one foot on the bottom edge of the ramp and stapled it on.

  18)   Now set up the ramp in its final position. Use some scraps of wood to support it in the exact position it will end up in.

  19)   Place the leveling wedge under the top of the ramp and measure the distance to the step or ground where it will rest. Mine was 30 cm. Now find flat scrap wood materials that will very closely match that dimension and cut to fit the step. I used some scrap particle board and boards from some leftover shelving. Make it at least as long as the ramp is wide and wide as the step is deep. Place these "riser" materials on the step or ground as required.

Any piece of scrap flat material can be used to build up the step till the ramp is flush with the landing

  20)   Add three short cross members between the runners . These will be needed as attachment points for the leveling wedge. It also adds some needed support for moving the ramp if portability is needed.  I added three staggered cross supports about three to four inches in from the upper end of the ramp.

  21)   If additional support is desired at the lower end of the ramp add three more cross supports there. I did this as I will be periodically moving the ramp in and out.

  22)   Now determine the final position of the leveling wedge under the top of the ramp. Place upper riser pieces and the leveling wedge in position. Now put the ramp, complete with surface finishing on top of the pieces and abut to the step threshold. Move the leveling piece forward or back until the main ramp is at the same height as the threshold. Make an alignment line through the leveling ramp and the outside runner on both sides.

Make a line through the leveling wedge at the point where the ramp is flush with the threshold 

  23)   Turn over the ramp and fasten the leveling ramp to the underside of the main ramp. Align the leveling piece with the lines made in the last step. Screw it to the cross members underneath.

  24)   Install rails on both sides of the ramp to prevent the wheelchair from running off the ramp; I used some pieces of scrap paneling.

  25)   Put the ramp back in position, test and use.