Truncated Dome FAQs

The use of truncated dome warning tiles has increased the accessibility and safety of public buildings and transportation for the visually impaired. As a property owner, you may have several questions about the selection, installation, and maintenance of truncated dome tiles to ensure your property complies with current ADA regulations. Keep reading to learn the answers to some of the most frequently asked questions regarding ADA warning tiles and how to implement them safely and effectively on any property.

Why Truncated Domes?

ADA specifications require the use of truncated dome warning tiles as a visual and tactile warning system for the visually impaired when navigating public streets, walkways, and other property. The use of truncated domes is required for two reasons: first, because of the feel of a truncated dome tile underfoot is unique and discernible even without visual input, and second, because the standardized use of truncated domes allows for the same level of safety and warning throughout the urban landscape, regardless of city or state. Thus, while other tactile warning systems may also be implemented to improve safety and traction, truncated dome warning tiles that meet federal standards are required by law on public walkways and in public transportation stations.

What Does Visual Contrast Mean?

Truncated dome warning tiles provide advanced and clear warning of changes in the path ahead. While the truncated dome design is meant to warn pedestrians without the need for additional visual information, truncated dome warning tiles must also contrast visually with their surroundings to assist pedestrians with full or partial visual acuity. The type of visual contrast required by the ADA regulations is dark-on-light or light-on-dark, meaning the tile must have a coloring opposite its surroundings. Furthermore, while there is no direct wording in the Americans with Disabilities Act regarding the color of the tile that supports the domes themselves, the Department of Justice, the Department of Transportation, the Federal Highway Administration, and the Federal Access Board have all agreed that the entire field or tile housing the domes, rather than just the domes, should be a single color to contrast visually with the surrounding material.

What Does the Installation Process Entail?

The installation process will depend upon the type of truncated dome warning tile that you choose. Cast-in-place tiles are placed in wet cement—after the cement has been poured and leveled, the tile is set in place, and then tamped down until any air that was trapped beneath is released. Once the tile is in place, a cinder block is used to weigh down the tile while the cement sets, which generally takes two to four hours. If you are installing a surface-mount tactile warning tile, you will not have to worry about pouring fresh cement. Instead, you simply need to ensure that the area is free of oil, grease, debris, and moisture. Next, an adhesive is applied to the underside of the tile, and the tile is set on the installation area. Once the tile is in the correct location, holes are drilled into the cement at the tile’s pre-formed fastener locations, and then the fasteners are hammered into place. The edges of the tile are then sealed with caulk, and the tile will then be ready for pedestrian traffic.

Do you have questions about meeting the current ADA requirements or installing and maintaining truncated dome warning tiles on your property? We produce a wide variety of federally-compliant truncated dome warning surfaces, including carbon composite and cast iron tiles. You can learn more about our truncated dome warning systems on our website, or by checking out our blog library for additional tips and news.