2010 ADA Standards for Accessible Design Pocket Guide
Ramp runs shall have a running slope not steeper than 1:12.
EXCEPTION: In existing sites, buildings, and facilities, ramps shall be permitted to have running slopes steeper than 1:12 complying with Table 405.2 where such slopes are necessary due to space limitations.
|Steeper than 1:10 but not steeper than 1:8||3 inches (75 mm)|
|Steeper than 1:12 but not steeper than 1:10||6 inches (150 mm)|
1. A slope steeper than 1:8 is prohibited.
Advisory 405.2 Slope. To accommodate the widest range of users, provide ramps with the least possible running slope and, wherever possible, accompany ramps with stairs for use by those individuals for whom distance presents a greater barrier than steps, e.g., people with heart disease or limited stamina.