The Who, What, Where, When and Why of Detectable Warning

Detectable warning applications became a topic of conversation when the Americans with Disabilities Act (ADA) was enacted in 1991. The ADA was controversial; so to find a middle ground amongst multiple interest groups they suspended the act for 10 years to review all of their issues. In 2001, after numerous studies the ADA was approved and it was now going to be enforced.

The ADA was exact with regards to detectable warning applications and the specifications necessary for compliance. A frequently asked question regarding detectable warnings is what and who they are for. Detectable warnings are intended to assist the visually and physically impaired; it notifies citizens of potentially oncoming vehicular traffic. The ADA requires detectable warnings to be installed on all curb ramps and sidewalks that lead an individual towards vehicular traffic. Now that we know the required locations of detectable warnings, let’s review the application specifications.

Detectable Warning

Detectable warning applications must exhibit several characteristics.

• A light on dark, and or dark on light surface that is adjacent to the substrate. This is measured by having a 70% contrast from the detectable warning surface to the adjacent surface (curb ramp).
• The surface must be able to create a unique sound that can be detected.
• Detectable under foot.
• The detectable warning surface cannot be a trip hazard and must have a slip resistant surface.
  Individual truncated domes are measured at the base, top and in height.
• The dome base diameter is to be between .9” and 1.4”.
• Dome tops are to have a minimum of 50% and maximum of 65% of the base diameter.
• Height requirements for each dome are exact at .2”.
  Dome spacing is measured in two ways, center to center and base to base.
• Two adjacent domes measured from center to center must be a minimum of 1.6” and maximum of 2.4” apart.
  Base to base the spacing must be .65”.

As the requirements for the detectable warning are specific, the materials used to manufacture these products are not. In researching this topic there are tons of material options, but one stood out amongst the class, stainless steel. Specifically with the Advantage Tactile brand, it offers a true 16 gauge stainless steel, exclusive duragrip color coating process and a 10 year warranty. The durability of this tile enabled for the lowest life cycle cost irrelevant of installation location. To find information on this product, federal requirements, and other detectable warning tile knowledge please go to www.advantagetactile.com.

by Shawn Osborne