Guidance on the 2010 ADA Standards for Accessible Design

Thresholds at Doorways. The 1991 Standards, at section 4.13.8, require the height of thresholds at doorways not to exceed ½ inch and thresholds at exterior sliding doors not to exceed ¾ inch. Sections 404.1 and 404.2.5 of the 2010 Standards require the height of thresholds at all doorways that are part of an accessible route not to exceed ½ inch. The 1991 Standards and the 2010 Standards require raised thresholds that exceed ¼ inch in height to be beveled on each side with a slope not steeper than 1:2. The 2010 Standards include an exception that exempts existing and altered thresholds that do not exceed ¾ inch in height and are beveled on each side from the requirement.