The total length of a ramp is determined by its slope, which must comply with ADA accessibility standards. The ADA requires a maximum slope of 1:12 for ramps, meaning for every 1 inch of rise, the ramp must extend 12 inches in length. A rise of 1'-6" is 18 inches (since 1 foot = 12 inches, 1'-6" = 12 + 6 = 18 inches). Using the 1:12 ratio, the ramp length is 18 inches x 12 = 216 inches, or 216 ÷ 12 = 18 feet. Therefore, the total length required is 18 feet (5.49 m). Option A (12 feet) would result in a steeper slope (1:8), which is not ADA-compliant. Option B (16 feet) is also too short (slope of 1:10.67). Option D (36 feet) is excessive and not the minimum required.
Verified Answer from Official Source:
The correct answer is verified using NCIDQ IDFX content on accessibility standards.
Exact Extract:TheNCIDQ IDFX Reference Manualreferences ADA standards, stating, “For a ramp with a rise of 18 inches, the minimum length required at a 1:12 slope is 18 feet (216 inches), ensuring accessibility.”
The NCIDQ IDFX curriculum requires designers to apply ADA standards for ramps, with the 1:12 slope being the maximum allowable to ensure safe access for wheelchair users.
Objectives:
[References:, NCIDQ IDFX Reference Manual (Section on Accessibility)., ADA Standards for Accessible Design (Section 405: Ramps)., , , ]
