Standards for Accessible Design

The 2010 ADA Standards for Accessible Design (Department of Justice, 2010) contains scope and technical requirements for accessibility to sites, buildings and elements by individuals with disabilities. The following discusses how our commercial lines of detectable warning pavers and truncated dome brick and concrete pavers comply with the applicable sections.
Floor and ground surfaces shall be stable, firm, and slip resistant.
Section 302.1
ANSI B101 testing was conducted by a third party firm on a selection of different finishes available for the Moduline series to determine the respective Dynamic Coefficient Of Friction (DCOF). The minimum requirements to achieve a high traction rating, meaning there is a low risk of slips and falls, are:

  • DCOF > 0.43 for level floors
  • DCOF > 0.46 for ramps up to 4.76 degrees

The results, which are summarized adjacent, show that most finishes, with the exception of a ground face sealed product tested wet, met the high traction rating. According to the National Floor Safety Institute, this will be viewed positively by the insurance underwriters.
Safety Direct America Bot-3000 universal walkway tester digital tribometer with printed data.
BOT-3000 Universal Walkway Tester Digital Tribometer
Openings in floor and ground surfaces shall not allow passage of a sphere more than ½ inch (13mm) diameter
Section 302.3
To verify the openings in a ground surface are compliant, a simple test is done to see if a ½ inch diameter sphere can pass through the opening. In the case of pavers, this test would be conducted on the joints in a relaxed state without jointing material in place.
Diagram of proper compliance regarding openings in a ground surface.
Changes in level of 1/4 inch (6.4 mm) high maximum shall be permitted to be vertical.
Section 303.2
Pavers, when installed correctly, are placed on a loose layer of bedding aggregate, then compacted down into it to set the pavers into place. One purpose of the bedding layer is to adjust for possible height variances in the paver thickness so that the final surface does not have any changes in elevation present.
Diagram of vertical change in level regarding detectable warning pavers with truncated domes.
Detectable warnings shall consist of truncated domes and shall comply with 705.
Section 705
The Moduline truncated dome pavers are manufactured in accordance with the new dome size and spacing requirements outlined in Section 705. Plus the modular size makes it easy to match the specified marking dimensions for curb ramps in Section 406.
Digital illustration of a moduline truncated dome unit from Belgard Commercial.
Detectable warning surfaces shall contrast visually with adjacent walking surfaces either light-on-dark or dark-on-light.
Section 70
Light Reflectance Value (LRV) testing was done on all of the NATIONAL COLORS to determine which pairings provide the required visual contrast. The test results are summarized in the adjacent table.
Diagram of typical spacer and top chamfer detail for Moduline Truncated Dome Pavers.
Studies at the University of Pittsburg 1 showed that for manual and power wheelchairs, use of 2mm chamfers would be acceptable for any route travelled by individuals using wheelchairs. The exposure limit results are actually better than that of a standard poured concrete sidewalk surface. The Moduline series includes a 2mm chamfer for that reason.

Reference Vibration Exposure of Individuals Using Wheelchairs over Concrete Paver Surfaces - University of Pittsburg, 2004.
Diagram of typical spacer and top chamfer detail for Moduline Truncated Dome Pavers.
2mm chamfers would be acceptable for any route travelled by individuals using wheelchairs.
Person in a wheelchair going over a concrete paver surface using Moduline Truncated Dome Pavers.