Americans with Disabilities Act Guidelines (ADA): Allowable slope for ramps more than 6 inch rise is 1:12 (one foot or ramp per inch of elevation)Rise of any ramp run must not exceed 30 inches without intermediate landingClear with of ramp must be 36 inches minimumPlatform must be a minimum of 60 inches in direction of travelAccess4U strongly recommends ADA guidelines be included in any ramp design