A safe wooden handicap ramp starts with the finished rise and enough run to stay at or below a 1:12 slope — one inch of rise for every twelve inches of length.
A bad ramp announces itself the moment a wheelchair tries to climb it: too steep, too narrow, or slick with rain. Getting a wooden handicap ramp right in the driveway starts with one number — the vertical rise from the ground to the threshold, not the door sill — because that single measurement decides how long the ramp must be and whether your yard has room for it.
Everything below covers the sizing math, the width and landing rules, and the wood-specific problems that trip up first-time builders. Wood is an acceptable material for an accessible route when it’s firm, stable, and maintained, but it rewards careful planning more than concrete or aluminum does.
What Slope And Run Do You Actually Need?
New accessible routes must not exceed 1:12 — eight and a third percent — and steeper slopes are allowed only in narrow existing-site situations, such as 1:10 for a six-inch rise or 1:8 for a three-inch rise. The U.S. Access Board’s ramp guide treats 1:12 as a ceiling, not a target, and recommends the flattest slope the site can handle.
To get the run length, multiply the rise in inches by twelve. A 24-inch rise needs at least 288 inches of ramp — 24 feet — before you add landings. Each run may rise no more than 30 inches, so anything taller needs an intermediate landing and a second run.
Measure the finished ground or landing surface to the threshold. Designing from door height alone is the most common error, and it produces a ramp that’s several inches short and noticeably steeper than planned.
Width, Landings, And Edge Protection
The minimum clear width is 36 inches, measured between handrails — not over them. Treat that as the floor, not the goal: check the wheelchair or scooter’s total width including armrests, controls, mirrors, and footrests, then leave margin.
Landings go at the top and bottom of every run and must be level, with only a limited drainage slope. Where the ramp changes direction, the landing needs to be at least 60 inches by 60 inches. Keep the cross slope no steeper than 1:48 so a wheelchair doesn’t drift sideways.
- Edge protection: any drop-off needs curbs of at least 2 inches, walls, or railings.
- Handrails: required on both sides when a run rises more than 6 inches or projects past 72 inches, set 34 to 38 inches above the surface.
- Clearance: allow 1½ inches between the handrail and the wall.
What Wood And Weather Demands Of You
Wood can be built to exact site dimensions and blended into a porch or railing, but exterior lumber needs outdoor-rated stock and ongoing protection against moisture, rot, warping, ice, and algae. Smooth, wet, painted, or icy boards are a genuine hazard — use a tested slip-resistant finish and keep the deck clear of snow, leaves, and standing water.
Fixed wood ramps usually need footings, structural attachment, permits, and inspection under state or local rules, and they are not portable. A ramp marketed as “ADA compliant” isn’t automatically right for your house; residential building, zoning, landlord, and HOA requirements can all add rules on top. The Access Board’s chapter on ramps is the place to check the current federal figures before you draw anything.
Whenever you’re ready to compare pre-built and kit options rather than build from scratch, our roundup of wooden handicap ramps worth considering covers what to look for in a spec sheet.
| Ramp Element | Requirement | Watch For |
|---|---|---|
| Maximum slope | 1:12 (8.33%) | Treat as ceiling, not goal |
| Steeper exception | 1:10 up to 6″ rise; 1:8 up to 3″ | Existing sites only; never above 1:8 |
| Run length | Rise × 12 | 24″ rise = 24 ft minimum |
| Maximum rise per run | 30 inches | Taller needs a mid landing |
| Clear width | 36 inches between handrails | Measure over the rails and fail |
| Turning landing | 60″ × 60″ | Must be level |
| Cross slope | 1:48 maximum | Sideways drift on steep yards |
| Handrails | Both sides over 6″ rise | 34–38″ high, 1½” wall gap |
How Do You Test And Inspect A Finished Ramp?
Run the actual wheelchair or scooter up and down it before you call the job done. Check turning room, braking, the approach angle at the threshold, and whether the user can descend safely without a caregiver compensating for a steep or narrow build.
Then inspect construction: continuous firm surface, secure framing, flush transitions, protected edges, and no loose boards, protruding fasteners, or splinters. After severe weather, recheck slope, fasteners, landings, and railings.
Don’t infer load capacity from lumber size. Get a documented load rating that covers the user, the wheelchair or scooter, a caregiver, and anything carried. And don’t borrow numbers from portable vehicle ramps — those specs, like a 30-inch clear width and 600-pound rating, apply to vehicle use, not your front steps.
Common Questions
Can I use a steeper slope if my yard is too short?
Only in specific existing-site cases: 1:10 for up to a six-inch rise, or 1:8 for up to three inches. Anything steeper isn’t permitted under the cited federal rule. If the space genuinely won’t fit a compliant run, consider a switchback design with properly sized intermediate landings rather than forcing a steep straight shot.
Do I need a permit for a wooden ramp at my house?
Often yes, though it varies. Fixed wood ramps may require footings, structural attachment, permits, and inspection under state or local rules. Call your local building department before buying lumber, and check any HOA, landlord, or historic-property rules too, since those can add requirements beyond the building code.
Is treated lumber safe and strong enough?
Wood can qualify as a firm, stable accessible-route surface when properly framed and maintained, and outdoor-rated lumber handles exposure better than interior stock. The catch is upkeep: moisture, rot, and ice attack wood over time, so plan on regular inspection and a tested slip-resistant finish rather than assuming it’s permanent.
Sources
- U.S. Access Board. “Chapter 4: Ramps and Curb Ramps” Source for slope, width, landing, and handrail figures.
- eCFR. “36 CFR § 1192.83 — Ramps” Federal rule text on ramp slope and exceptions.
- Commonwealth of Massachusetts. “Notes on Walks and Wheelchair Ramps for Designers and Construction Engineers” Construction and weather-durability guidance.