North Carolina Building Contractor License Practice Exam

For ramp design, what is the ratio of rise to run that is typically acceptable?

1. 1:30

2. 1:12

3. 1:20

4. 1:10

The correct answer is: 1:12

The typical acceptable ratio of rise to run for ramp design is 1:12. This means that for every inch of vertical rise, there should be at least 12 inches of ramp run. This ratio is critical for ensuring accessibility, particularly for individuals using wheelchairs or other mobility aids. A slope of 1:12 is considered to be gentle enough to allow for safe maneuverability and prevents the risk of tipping or falling. This standard is aligned with the Americans with Disabilities Act (ADA) guidelines, which aim to make public spaces more accessible and ensure that ramps are usable by people with various disabilities. The design consideration helps to create a balance between functional use and safety, making it a vital aspect of ramp construction in both commercial and residential properties. Other ratios mentioned, while potentially used in different contexts, do not meet the accessibility standards set forth by the ADA for general-purpose ramps like those leading into buildings. Thus, the 1:12 ratio is widely accepted and enforced in building codes and practices concerning accessibility features.