Question: what is a 1/12 slope?
Answer: 1:12 slope ratio (ADA Recommended) means that for every inch of rise, you will need one foot of ramp. As an example, a 12 inch rise would require a 12 foot ramp to achieve a 1:12 ratio. 2:12 slope ratio means that for every two inches of rise, you would need one foot of ramp.