What is the maximum threshold height allowed for sliding doors under ADA guidelines?

• A. Threshold height should be 1/2 inch for sliding doors.
• B. Threshold height should be 1 inch for sliding doors.
• C. Threshold height should be 3/8 inch for sliding doors.
• D. Threshold should be less than 3/4 inch for sliding doors.

Answer: (D)

Accessibility hinges on keeping doorway changes in level small so wheelchairs and other mobility devices can move smoothly. For sliding doors, the threshold height must be limited to prevent creating a barrier at the doorway. The maximum height allowed by ADA guidelines is a threshold under 3/4 inch. This means any threshold should be no higher than three quarters of an inch, with beveled edges to ease passage. If a door would exceed this height, a ramp or a different threshold design is needed to maintain accessibility. The other options set heights that are either clearly lower than the maximum or exceed the allowed limit, so they don’t reflect the true maximum.