Building a ramp? Use your angles.
The angle1 inch of rise per 12 inches of ramp (about 4.8°)
ADA guidelines limit an accessible ramp to a slope of 1:12: one inch of rise for every foot of length, about 8.3%. A ramp rising 24 inches needs at least 24 feet of ramp, so long ramps switch back with level landings, just like a trail.
The video for this angle is on its way.
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How to do it
- Measure the total rise in inches from the ground to the threshold.
- Multiply by 12 to get the minimum ramp length in inches.
- Plan level landings between runs on long ramps.
- Where space is tight, switch back with a landing at each turn.
- Check your local code. It can be stricter than the federal minimum.
How long a ramp?
Why it works
A shallow slope lets people in manual wheelchairs push up without losing control, and come down safely. When the length doesn't fit, the ramp folds back on itself instead of getting steeper.
Questions
Is 1:12 the law for my home?
The ADA covers public accommodations. Homes aren't required to meet it, but 1:12 or gentler is still the best guide.
Can I go steeper for a short ramp?
Some codes allow steeper slopes for very short rises. Check local rules, and remember steeper is harder for everyone.