Detectable Warning Tiles , Are Not Always Detectable

Working with municipalities, developers, and contractors I often hear variations of stories and opinions regarding their overlapping projects.  Sifting through all of it to find a middle ground can be a challenge, but one message that rings true is a desire to purchase the best products at competitive prices.  In the world of detectable warning tiles we see numerous products boasting superiority in all areas of compliance.  After all of the boasting comes field installation, that is where pardon the pun, the rubber meets the road.

The issues that are of most concern to end users of detectable warning tiles revolve around durability and maintenance.  Our durability issue primarily focuses on damage to truncated domes.  This damage can be caused by vehicles, industrial equipment and foot traffic depending on the manufacturing material.  Once the truncated domes are compromised, it becomes a non-compliant product.  Detectable warning tiles are required by the Americans with Disabilities Act (ADA) to have a couple of specific characteristics.  The first requirement is that all detectable warning tiles must have truncated domes.  These domes also have exact specifications.

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”. 

In regards to the second concern of maintenance, ADA requirements specify several detectable characteristics.  They may seem simple, but with some materials, specifically concrete, rubber and cast iron you are unable to have a long lasting color finish.  This creates a necessity to paint these surfaces on an annual basis for ADA compliance.  

• 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. 

After reviewing multiple field installations I have come to the opinion that the most durable tile available on the market today is manufactured from stainless steel.  My rationale goes back to our two primary concerns, durability and maintenance.  In regards to durability with stainless steel, the Advantage Tile product (www.advantagetactile.com) is a 16 gauge steel with pressed truncated domes.  The second issue of maintenance is resolved with the Advantage Tile’s duragrip finish.  This finish will not peel or rust and will require minimum maintenance.  Did I mention the 10 year warranty they also provide with the product?  I detect that many of you will be visiting their website and specifications soon. 

- by Shawn Osborne