Determining Ramp Slope
Permanent Wheelchair Ramp Slope
The National Building code specifies at least a 1:12 slope on all permanently installed wheelchair ramps. What this means is, for every inch of rise from the beginning of the ramp to the end of the ramp there must be at least 12" of ramp.
So for a rise of 14" from beginning of the ramp to the end you would require at least 14' of ramp.
Portable Wheelchair Ramp Slope
Building codes do not apply to portable ramps unless permanently installed. That said, ramp manufacturers have recommendations and guidlines on how steep a grade their equipment can be safely used.
While there will be some variation between ramp manufacturers, a loose guide would be 2:12 for occupied wheelchairs and scooters and 3:12 for unoccupied wheelchairs and scooters.
Equipment Considerations
Wheelchair and scooter manufacturers have recommendations on how steep a grade their products can safely negotiate and these limits should be considered when choosing a ramp length.
Most wheelchairs and scooters can accomodate slopes up to 9 (almost a 2:12 slope) degrees but variations in seat heights, wheel placement and user abilities will have an effect on stability and safety on slopes.
