This plan includes my article on a translation of the Building Code into simple layman's terms for building residential ramps for the disabled in wheelchairs. I have given the desired slope and width, as well as height of handrails and curb.
[For more information on How to Build a Wheelchair Ramp, see my article: How to Build a Wheelchair Ramp]
I have noticed an interest from members of our website about the specifications of building a ramp for a disabled person entering their home. Most Building Codes are very specific about the requirements for ramps. In the United States, there is The Americans with Disabilities Act, which outlines the dimensions for ramps. Let's go over the key points for building a ramp to gain access to the interior of your house, in simple terms. It is always a good idea to checkout your local building codes, as well.
Ramps are necessary for individuals in wheelchairs, as well as those pushing strollers, grocery carts and the elderly or infirm to access the entrance to a home. A ramp should have a level area at the bottom as well as the top and at changes of direction. Some long ramps over 20 feet should have a level spot in the middle. These level areas or landings should be the width of the ramp and at least 5' long. This allows the wheelchair driver to negotiate a turn and the chance to slow down or just to stop and rest. The ideal width of a ramp is 36" between handrails. Handrails are installed on both sides of the ramp. This allows the wheelchair driver to grab the handrails and pull himself or herself along. The preferred height of the top of a handrail is also 36", another rail at 18" is helpful for those unable to reach the higher rail, children, for example. The handrail should be continuous and returned into the wall, floor or post or the end rounded to avoid someone running into it.
The slope of the ramp should be not less than 1' in 12', except for very short ramps. This means that if the vertical rise in the ramp is 1' high the horizontal distance should be at least 12' long. Curved ramps should be avoided due to difficulties negotiating curves in a wheelchair; better to have a landing instead.
The ramp should have a 3" high curb to prevent the front wheel of the wheelchair from going off the edge. This curb can be incorporated with the handrail, having a bottom rail not more than 3" above the deck. Any difference in height or projection on the ramp should not be more than ½", for example where the plywood sits on the sidewalk at the start of the slope.
Ramps can be constructed of wood, concrete or steel. Make sure the surface is slip resistant and that level areas cannot hold puddles of water and will not build up ice during the winter. In many areas, the cost of building a ramp for the disabled can be deducted from your income tax.
Following is a plan for a straight 12' long wheelchair ramp with handrails.
All dimension lumber and plywood should be Pressure Treated Wood (PTW)
As mentioned in the article, the ramp should start with a level landing at its lower end as well as a level landing at its upper end. The lower end is usually the sidewalk or ground.
The upper end will be built over the top step or porch to arrive at the height of the threshold of the door. Make this landing the width of the ramp and about 5' long. If height is limited, use plywood or dimension lumber as packing under the plywood deck. If enough room, construct joists on posts, as shown. Be sure to put a plywood scab over the joint of the post and joist to keep it ridgid.
When building the ramp, remember to keep the slope greater or equal to 1 in 12. Measure the total height difference of the ramp from the sidewalk or ground to the door threshold. Convert the height difference into decimals of feet or inches, then multiply by 12 feet, respectively. For example, if the height is 1.5 feet or 18 inches multiply 1.5' x 12 = 18' or 18"x 12 = 216" / 12 = 18'. If the ramp length is over 20', put a landing in the middle which also gives a chance to change directions.
Once the length is determined, start by fastening a string line to the end of the upper level landing at threshold height and to the correct length on the sidewalk. Make a template for the joist by going to the lower end of the string with a short 2x4 and mark the position of the 2x4, where it has full width, allowing 3/4" for the plywood. Place another 2x4 on the flat, laying on the ground or sidewalk against the short 2x4, scribe on top of the flat piece marking the end cut of the joist. The joist will sit on this thickness of pad. It is never good building practice to bring a structural member to a sharp point. It allows easy rot and decay, a blunt end will last longer. Mark the angle of the joist at the upper end, as well, on a short piece of 2x4.
Cut the ends off the joists to match your template. Start at the upper end, building a ledger supported by posts. Keep in mind how you are going to brace your handrails. Notice the drawing shows the handrail posts extending from the ledger posts, then are doubled up on the inside. An alternate method of bracing the handrail, if restricted by limited height, other than embedding the post in a concrete filled hole, is shown in this drawing:
Construct a series of ledgers and doubled up posts to hold up the longitudinal joists at least every 3'. Toe-nail the joists to the ledgers. The handrail supports should be extended from the posts at least every 6'. Don't just support structural members with nails or screws. Always support these members with 2x4s, etc. such as shown for the ledger support.
In order to make the surface of the ramp non-slip, apply asphalt roofing, or paint with a floor enamel with either silica sand or chopped walnut shells added.
Every ramp is different, so be innovative with how you support the ledgers. At the bottom end use packing of 2x_ lumber or plywood in a continuous strip across the plywood. Nail or screw the blocks together to prevent shifting.
For permanent exterior projects such as this, I recommend using Exterior Carpenter's Glue in the joints and sealing the wood with a good quality oil stain or acrylic latex paint.
Dave(Ask Dave) (About Dave)
Hi, I'm Dave Osborne. With over 50 years experience as a journeyman carpenter, foreman and contractor in heavy construction I enjoyed working with apprentices and sharing the tricks of the trade that others shared with me. Now I get emails from Members all over the world and we include many of my answers in our Free Monthly Newsletters. Some of my answers include drawings and instructions specific to a project, but may also answer your questions. I use correct construction terminology, so you can confidently inform your building supply dealers or contractors exactly what you need.
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