We often get asked about openings in floor surfaces, and how big these openings can be in order to meet the AS 1428.1 standards.
AS 1428.1 Clause 7.5 accepts that a grate may be used on a continuous accessible path of travel if circular openings are not greater than 13mm in diameter. This Clause also states that slotted openings shall not be greater than 13mm wide, and they must be oriented so that the long dimension is transverse to the dominant direction of travel. When the slotted openings are less than 8mm, then the length of the slots may continue across the width of paths of travel.
If floor openings are too wide i.e. more than 13mm, this can capture the small front wheels of a wheelchair, or the end of a crutch or cane, possibly leading to a trip or a fall.
In the following video, we see an example of an accessible route whereby the grate has been positioned in the wrong direction. The correct way to install the grates along the path of travel would have been like that shown in the pictures above.
Images referenced from:
http://www7.mississauga.ca/Departments/Marketing/Websites/Accessibility/Mississauga_FADS.html#a4.1.7