Building a wooden ramp overview
Ramp prices depend on the overall length, the number of landings, the materials (wood or aluminum), and whether you build it yourself or hire a contractor. You can build one yourself for a materials price of about $35 per lin. ft., or hire a ramp contractor to build it for you in a day or two for about $100 per lin. ft.
Prefabricated wheelchair ramp kits with aluminum sections cost about $100 per lin. ft., and you can assemble the sections yourself. But they take a while to order and ship. Or you can hire a company to design and install an aluminum access ramp for about $150 per lin. ft. You can get ramp design advice, contractor referrals, help from community volunteers and even financial assistance from more than 350 nonprofit organizations nationwide. Just search online for ‘ramp project (your state)’ to find them for your location.
We’ve seen some pretty scary DIY ramps, so we contacted the experts at the Metropolitan Center for Independent Living, publishers of the booklet ‘How to Build Ramps for Home Accessibility’ (get the booklet and DVD). They referred us to Warren Moe Construction, a ramp contractor in Minneapolis. Warren walked us through the basics of building a wood ramp and let us know the most common DIY ramp-building mistakes as well as handicap ramp code. With basic carpentry skills and a miter saw, router, drill, level and framing nailer, you can build your own ramp. Here’s the process.
Measure and design your handicap accessible ramp
Start by measuring the distance from the threshold to the ground at the Installing a handicap ramp most accessible exterior door. Then determine the preliminary access ramp length. A gentle 1:20 slope (1 in. of rise requires 20 in. of run length) is best for ease of use but requires a longer, more expensive ramp. If your yard isn’t large enough to accommodate that length, add switchbacks and landings or build a ramp with a slightly steeper grade (the steepest ramp slope allowed is 1:12). Follow ramp-building guidelines and handicap ramp code and adjust the ramp length and slope to account for grade changes in your yard.
Figure A: Wooden ramp landings for turns
Figure B: Landings for switchbacks
Get approvals and permits
Most building codes require a permit and inspection if the wooden ramp is 30 in. or more above the ground. In addition, some locations require frost-proof footings for permanently installed ramps, while others allow you to set the ramp on treated plywood pads if it’s for temporary use. Plus, many homeowner associations require design and material preapproval before you can start the project. Check all those requirements and get all your approvals and permits well before any trips to the lumberyard.
Build the wooden ramp in modules
Building the ramp in place with long spans is a common DIY mistake. Long spans are harder to adjust and impossible to reconfigure if the original design proves unworkable. Instead, build individual modules and bolt them together at the vertical supports. Later on, you can disassemble and sell the modules to recoup your investment when the ramp is no longer needed.
Figure C: Ramp width and height
Mind the gap
The two most important areas on a ramp are where the upper landing butts up to the door threshold and where the ramp transitions to the ground. The upper landing must be level or within 3/8 in. of the threshold. A larger gap will abruptly stop the wheelchair’s front wheels.
Calculate slope and end point for your access ramp
Use the slope formula to calculate the ramp’s end point. For a residential wheelchair ramp slope, multiply the distance from the threshold to the ground by the preferred slope. That’ll give you the ending point from the house (not the actual ramp length), if the ramp is built in a straight line. To determine the actual ramp length to calculate a bill of materials, find the square root of the sum of the rise height squared and the distance from the house squared. Then add the lengths of the landings.
The important dimensions for a wooden ramp: Handicap ramp specs
Door landings should be large enough (at least 58 x 60 in.) to allow a wheelchair occupant to open the door and back up without rolling onto the sloped area. Allow extra elbow room (12 to 24 in.) on the handle side for out-swing doors. A 58 x 60-in. landing is adequate for 90-degree turns (Figure A), but must be 58 x 96 in. (Figure B) for 180-degree switchback turns. If the ramp includes long stretches, include an intermediate level landing as a rest area.
Making the ramp too narrow is also a common DIY mistake. The ramp must have at least 36-in. side-to-side clear space and a maximum 36-in. spacing from the ramp floor to the top of the handrails (Figure C).
Before you proceed, draw a detailed sketch of your ramp, showing ramp width, landing size and site location.
Local codes trump our advice
Local building authorities have the final word on all designs and specifications. Don’t wait until your ramp is built to discover that it doesn’t meet your local codes. Get your plans reviewed by a local building inspector first so you don’t have to redo your hard work.