Granular decision making by the project team should be guided by this notion, for example in the selection of flooring materials or wall finishes. From the perspective of occupant health and safety, architects and contractors must consider trip hazards, wall projections, and the likelihood that users might slip and fall on a given type of surface. Yet slip resistance does more than impact the liability of the architect, contractor and owner-operator: It also presents an enterprise cost (lost productivity or increased absenteeism, for example) as well as a societal cost in health-care needs and potentially in litigation. In this way, good resistance to trip hazards and slipping accidents is a dimension of blue sustainability.

To assess this variable, the most reliable means of determining slip resistance is the dynamic coefficient of friction (DCoF), a measure that can be gauged with a recently developed TCNA standard. Introducing the 2012 test, the industry council noted that DCoF measures “the frictional resistance one pushes against when already in motion,” which in practical terms means how slippery a wet surface feels to someone walking over it. The DCoF test replaces the previous test for static coefficient of friction—given as SCoF or simply CoF in the literature—because it is more repeatable and “better relates to slips occurring while a person is in motion,” says TCNA, making it a more accurate real-world determinant of slip resistance.
           
Using a newly developed portable sensor device with automated functions, the DCoF test method employs a 0.05 percent sodium lauryl sulfate solution to “measure the interaction between the sensor, the lubricant, and the [floor] surface under controlled conditions.” The DCoF test also sets a minimum value in the ANSI A137.1 standard for wet floors of 0.42, which equates to slightly above the 0.60 SCoF value previously recommended by ADA that represents one well-known industry benchmark for commercial flooring. This SCoF standard came about following a series of National Floor Safety Institute (NFSI) tests determining that values of 0.60 or greater reduce slip-and-fall incidents and claims by as much as 90 percent.

Because the ceramic tile industry uses the more relevant DCoF measurement, practically as well as technically all tile flooring products approved by the TCNA exceed the flooring industry threshold for slip resistance, making them a smart and safe choice contributing to blue design benefits.

Universal Design, Testing and Tile

Another essential element of blue design’s occupant health and safety focus is accessibility. Ensuring universal access to buildings has become a major component of design throughout the past several decades, with the accessible design movement and its focus on addressing disabilities evolving into universal design and an emphasis on accommodating a full range of human diversity.

From a universal design standpoint, tile is a highly versatile material. For example, the resilient surfaces offer easier movement for wheelchairs or walkers than carpeting, and in fact is an ideal way to meet ADA Accessibility Guidelines standards for Floor or Ground Surfaces (302). Tile characteristics relevant to the ADA include:

• firm, in that it resists deformation by applied forces;
• stable, in that it resists movement;
• accessible, because it remains unchanged by external forces, objects, or materials; and
• slip resistant (302.1), based on testing and NFSI requirements.

This combination of firmness, stability, accessibility, and slip-resistance makes tile a safe, effective choice not only for level surfaces but also for ramps and other sloped surfaces.

Yet tile is also a resilient material in the sense that it is strong enough to handle impacts from falls and dropped objects. It can also tolerate large point loads and area loading without breaking. Other flooring products display durability and strength, yet tile also has other qualities that give it blue design benefits. In particular, engineered vinyl (widely marketed as “resilient flooring”) and other flooring materials may be produced using toxic or polluting chemical compounds in the production or finishing processes.

This is not the case for ceramic tile, which has no VOCs or other noxious constituent materials. This quality—termed inert or environmentally benign by the EPA and other groups—constitutes another primary health and safety benefit of ceramic tile. The chemically inert nature of tile not only makes the material safer for interaction by occupants, but also exempts it from many certification processes that are referenced in LEED and other green building programs.

According to BuildingGreen’s LEEDuser, “Resilient flooring, rubber flooring, and prefinished wood flooring all must be FloorScore or Greenguard Gold certified” to obtain the LEED 2009 credit IEQc4.3: Low-Emitting Materials—Flooring Systems. “Carpeting and carpet cushion need to be CRI Green Label Plus or Green Label certified (respectively),” LEEDuser adds. In both options offered to obtain the credit, LEED specifically says that ceramic tile, masonry, terrazzo, cut stone, and solid wood floorings “qualify for credit without testing.” Tile setting adhesives and grout, however, must conform to VOC limits set forth in the 2005 version of Rule 1168 of the South Coast Air Quality Management District (SCAQMD) guidelines.

Savvy architects counsel their clients regarding the benefits of not having to test finish materials, including ceramic tile. GreenGuard has become an important certification and often leads to single-attribute product specification. But there is growing appreciation among end-users that GreenGuard is only needed with product formulations that carry the health risks of toxic constituents; ceramic tile and natural stone do not carry such risks. Other flooring systems such as rubber, prefinished wood, and carpet must be FloorScore or GreenGuard certified in order to achieve LEED credits. Tile is a non-VOC material and immediately qualifies for credit without testing under NC-2009 IEQc4.3.