IB
Institute of Builders

ADA Accessibility

The Department of Justice's 2010 ADA Standards for Accessible Design are strict. Being off by a quarter of an inch on a ramp slope will result in failed inspections and legal liability.

Ramp Slope Calculator (1:12 Max)

Section 405.2 requires that ramp runs have a running slope not steeper than 1:12. Cross slope shall not be steeper than 1:48. Calculate required run length based on elevation change.

Minimum Required Ramp Run Length (1:12)
Warning: Runs over 30 inches of rise require a resting landing (Sec. 405.6).

Common Clearance Mistakes

Element Requirement Common Failure
Door Clear Width 32 inches minimum (Sec. 404.2.3) Measuring frame-to-frame instead of face-of-door to stop.
Grab Bars 33-36 inches AFF (Sec. 609.4) Failing to block walls securely; must support 250 lbs point load.