Wheelchair Ramps in Los Angeles: Slope, Landings and the Numbers That Decide the Design

Every ramp starts with one measurement: the vertical distance from the lower surface to the upper one. Everything else follows from it, and it follows mathematically.

This is why so many ramp projects stall. People imagine a ramp fitting where a set of steps is, and a ramp needs many times the horizontal distance that steps do.

The slope ratio, and what it means in feet

The accessibility standard for a ramp is a maximum slope of one unit of rise for every twelve units of run — commonly written 1:12. A steeper ramp is harder or impossible to use independently in a manual chair, and it is dangerous going down.

Translated: every inch of height needs a foot of ramp.

A thirty-inch rise — a typical three-step entry — needs thirty feet of ramp, before landings. That is the number that surprises people.

Gentler is better where space allows. A 1:16 or 1:20 slope is noticeably easier to use, and if you have the room it is worth using it.

California's residential code permits ramps at 1:12, with an exception allowing steeper where it is technically infeasible to do otherwise. That exception exists for real constraints — it is not a design preference, and a steeper ramp is genuinely harder to use.

Landings, which are where the length really goes

A ramp cannot just keep going. The standard limits the vertical rise in a single run — commonly thirty inches — before a level landing is required.

Landings also go at the top and at the bottom, and anywhere the ramp changes direction.

Requirements that matter:

• Landings must be level. Not almost level.

• A landing has a minimum length, commonly sixty inches, and must be at least as wide as the ramp.

• Where a ramp changes direction, the landing has to be large enough to turn in.

• At a door, the landing has to provide maneuvering clearance, and the amount depends on which way the door swings and which side the person approaches from. A door that swings out onto the landing needs more room.

That last one is the detail most commonly missed on a homeowner-built ramp. A landing sized for the ramp but not for the door means someone in a chair cannot open the door without rolling backward off the landing.

Width, cross slope and the running surface

• Clear width between handrails has a minimum, commonly thirty-six inches. Wider is better, and for a powered chair meaningfully better.

• Cross slope — the side-to-side tilt — has to be nearly flat. A ramp that tilts sideways pulls a chair toward the low edge the whole way down.

• The surface must be slip resistant, wet and dry. A smooth troweled concrete ramp is dangerous in rain.

• Edge protection is required — a curb or barrier along the open sides so a wheel cannot roll off.

Handrails

Handrails are required on ramps above a modest rise, and generally on both sides. The height range, the graspable shape, the clearance from the wall and the extensions at the top and bottom are all specified.

The extensions matter more than they sound. A handrail that stops exactly at the end of the slope gives someone nothing to hold at the moment they most need it. The full detail is in handrails and guardrails on a ramp.

Residential versus public — two different standards

A ramp at a private home is governed by the residential code. A ramp serving a business or any place of public accommodation is governed by the accessibility chapter of the building code, and those requirements are more detailed and more strictly enforced.

If there is any chance the property will be used commercially, or rented in a way that triggers accessibility rules, build to the stricter standard. Retrofitting a residential ramp to commercial standards usually means rebuilding it.

The commercial side is in ADA ramps for a business in Riverside County.

When a ramp will not fit

This happens, and it is better to face it early. A high entry on a small lot may simply not have thirty or forty feet of run available in any configuration.

The options then:

1. Switch entrances. A side or back door with a lower rise may need a fraction of the length.

2. Switch to a different form. A vertical platform lift handles a large rise in a small footprint.

3. Regrade. Sometimes raising the ground at the approach reduces the rise enough to make a ramp fit, though this brings drainage into it.

4. Switch direction, using a switchback with a turning landing to fit the run into a smaller area.

The lift comparison is in ramp or lift for a home in Temecula and Murrieta.

Drainage, because it is a ramp in the rain

Water must not stand on a ramp, and the ramp must not direct water at the door it serves. A ramp that sheds toward the house delivers water to a threshold, and a threshold is the easiest place for water to get inside.

Landings are the problem spot, because they are level by definition. They need just enough fall to drain without violating the level requirement, and the water needs somewhere to go.

The signs of getting this wrong are the same as anywhere else against a structure — see water against the house.

Start with these three numbers

1. The total rise, measured from the finished lower surface to the finished upper surface.

2. The horizontal distance actually available, including where a turn could go.

3. The door swing and the approach direction at the top.

With those three, a ramp either fits or it does not, and you know before anyone designs anything.

Ramps are usually needed sooner than expected, and the first question is always whether one fits. Book a free 15-minute call or call (323) 651-0635 and tell us the height from the ground to the door. That number decides most of the design.

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