Anti-Slip & Accessibility
November 1st, 2005


By Beth Rogers

November-December 2005

The Americans with Disabilities Act (ADA), enacted in July of 1990, provides civil rights protections to people with disabilities. Not only does it protect those individuals from being discriminated against in terms of employment but it also addresses design to ensure that they are not physically impeded from access to areas that able-bodied people routinely enjoy. Structures that need to be ADA compliant are places of public accommodation and commercial facilities in the private sector, as well as all federal, state, and local government facilities. The Act applies to structures that are built new or altered.

The Act has greatly impacted design and choice of materials in the past 15 years. In drafting the ADA Accessibility Guidelines for Buildings and Facilities (ADAAG), accessibility at places as varied as fishing piers and amusement parks is outlined and the structure of things ranging from automated teller machines to floor and ground surfaces is also addressed.

In a technical bulletin regarding floor and ground surfaces, the Access Board, an independent federal agency that provides information on accessible design, notes that 27 million Americans have some problem walking, of which more than a third report a severe problem: “Ambulatory persons with mobility impairments—especially those who use walking aids—are particularly at risk of slipping and falling, even on level surfaces.”

In a nutshell, the ADA’s guidelines for ground surfaces require them to be “stable, firm, and slip resistant.” “Stable” is interpreted to mean that the surface remain “unchanged by contaminants or applied force.” Firm means it “resists deformation by either indentations or particles moving on its surface” and slip resistant means the surface “provides sufficient frictional counterforce to the forces exerted in walking to permit safe ambulation.”

Most would agree that ceramic tile, provided that the proper substrate is used, meets the first two requirements. Problems arise when it comes to slip resistance. Slip resistance is measured as the “minimum tangential force necessary to initiate sliding of a body over the surface and the body gravity force. The coefficient of friction between the two surfaces is the ratio of the horizontal and vertical forces required to move one surface over another to the total force pressing the two surfaces together.”

Dave Yanchulis, an accessibilities specialist with the Access Board, admits that the government hasn’t been able to nail down a requirement for slip resistance, explaining, “The reason is that there isn’t a uniform test procedure for measuring slip resistance so we can’t specify a value without a uniform test method in place.”

Therefore, without corroborating research, values for slip resistance are not specified in the ADAAG and manufacturers of flooring surfaces seem to have leeway to interpret the Act’s parameters. As Yanchulis explains, “We understand that there are some norms in the industry regarding slip resistance levels based on which measuring method you use.” However, the Access Board recommends a static coefficient of friction of .6, while the Occupational Safety and Health Administration recommends a static coefficient of friction of .5 (a higher number reflects more friction or slip resistance).

However, as the Board notes, “some slippage is in fact necessary for walking, especially for persons with restricted gaits who may drag their feet slightly….a very high coefficient of friction may actually hinder safe and comfortable ambulation by persons with disabilities.”

The government doesn’t favor one material over another when it comes to floor and ground surfaces. “We generally don’t call out accessible or non-accessible materials as long as our three criteria are met,” explains Yanchulis. “We don’t rule anything out although some materials certainly raise questions, such as a very loose, gravelly material for an outdoor trail, for example, or a very highly-polished surface for an interior.”

Markku Allison, a resource architect with the American Institute of Architects, agrees: “When you’re looking at accessibility issues, I have not seen a strong correlation between surface selection and accessibility. Within a particular surface family, like tile, there might be certain products that meet standards better or worse for accessibility issues. For example, if you’re working with stone floors, you might not use a polished granite—you would use a textured granite for better traction…You try to imagine the situations where someone’s coming across the floor in a walker, and think about what makes it safest and most easily traversed.”

Allison notes that a wide range of tile products are slip resistant, whether due to special coatings that have been applied or the actual texture of the tile. As he points out, “you see tile in most restaurant kitchens…where slip resistance is a huge issue.”

For graded surfaces, like ramps, the Access Board notes that ceramic tile might not be appropriate. If it is used, the Board suggests tile that has a coefficient of friction of .8. However, Allison notes that ramps that connect Washington, DC’s subway system to Reagan National Airport have used tile successfully.

Thomas Klose, principal of Thomas F. Klose Architect, Inc. of McLean, VA, says, “Ceramic tile is a good surface compared to carpeting, especially if you need to roll a wheelchair on it.” Klose specified tile for a job he did at DuPont’s corporate headquarters in Wilmington, DE. “The things we were looking for there were a smooth surface, meaning that the edges of the tile weren’t tumbled or rustic in any way, and we used small joints, like 1/16 of an inch and tried to get the mortar joints flush with that…Smooth is good. Falling is a fear for people in wheelchairs or on crutches.” Klose adds that an unpolished surface is also good, and he always specifies matte tile because it has a “tooth” to it.

Dave Milanowycz, northern regional sales manager with Lakeland, FL-based Florida Tile, notes that starting last June any new glazed porcelain floor tiles the company produces will automatically be ADA compliant. The new tile now has a coefficient rating of at least .6 wet or .8 dry. Through the attrition of old lines, Milanowycz predicts that eventually all of Florida Tile’s floor tile will one day be ADA compliant.

Milanowycz notes that the corporate decision was prompted after the company, whose product is used mainly in the residential market (although the new line is suitable for commercial purposes), started fielding more concerns from builders who are catering to an aging population. “We do a lot with builders that cater to 55 plus communities and as you see those communities aging, they’re looking for more ADA compliant floor tiles, because they know they’re going to need it in the future or have an elderly relative live with them.”

It used to be only architects that would spec ADA compliant tile, says Milanowycz. Today builders and even individuals are asking for the product. Consequently, having an ADA-compliant product is a strong selling point. Milanowycz notes that his own mother, who is 75, picked slip resistance above any other quality when she recently tiled her kitchen. “That doesn’t mean that aesthetics are compromised,” Milanowycz is quick to add. “If you saw them you’d go crazy and say this is a gorgeous look.”

There’s nothing about Florida Tile’s ADA-compliant tile that shouts that it helps with accessibility, but Milanowycz does note that it has a matte finish. “You’re not going to get a high shine in ADA compliant,” observes Milanowycz, “but the glazes have come a long way.” He adds that glazes in development overseas are promising to deliver both high shine and slip resistance. He also notes that tiles can be designed with a greater than .8 coefficient of friction but they tend to degrade footwear and be hard to clean.

While demand for tile is often regional, Milanowycz says it’s a trend in those who are over age 55 to use tile throughout their homes, regardless of where they live. “They’ve been through the wood, they’ve been through the carpet, they’ve been through other flooring materials, so now the most proven factor for them has been tile…We’re definitely seeing a higher percentage of tile used in the aging community and a lot of times they’re looking for more ADA compliant tile. They want slip resistance and no maintenance.”

There are other ways that tile can assist people with disabilities. Not only can it provide a safe surface for those with impaired mobility, but special tile surfaces can help the visually impaired. For example, the Washington Metro system has a band of bumpy tile at the edge of the subway platform that tactilely alerts commuters to the fact that they’re at the edge. Allison notes that many urban areas use grooved tile in curb cuts to both alert blind people to the change in elevation and make the cuts more slip resistant.

Adding Slip Protection

There are numerous products on the market meant to be applied to existing tile so that it conforms to the slip resistant requirements of the ADA .

Peter Ahern, owner of Spring Valley, CA-based Slip-Tech, said his company started by serendipitous accident in 1984. He was living near Silicon Valley , where silicon chips are routinely etched out with hydrofluoric acid. Some acid spilled on a tile floor in a chip lab and workers discovered that the floor was much harder to mop. A friend of Ahern’s in the tile business got called in to diagnose the problem and that gave Ahern the idea that he could make a lot of money using hydrofluoric acid as an anti-slip device. Ahern notes that all anti-slip manufacturers rely on hydrofluoric acid, which is why no one has an exclusive patent on anti-slip products.

Ceramic floors might be less slick but, Ahern is quick to point out, deglazing does make tile harder to clean. Electron photographs taken of treated tile show that the acid opens up air holes in the tile and dirt gets trapped in the spheroids. Consequently, Ahern notes that the product shouldn’t be used on white floors and he’s turned down jobs on white tile. Cream colors are less of a problem but with light colors, cautions Ahern, “you have to be careful in the degree at which you etch it.” He normally treats light tiles less than darker ones.

One such product is manufactured by Slip Guard Systems, Inc. of Orange Park, FL. Company owner Jay Dorsett notes that the floor must be cleaned properly before the etcher and neutralizer are applied. As Dorsett notes, product that is not put down on a thoroughly-cleaned floor has a tendency to bead up and then treated areas stand out against non-treated areas.

Most Slip Guard is sold through tile dealers who “are trying to solve problems.” “I hear every day,” notes Dorsett, “people say ‘this is supposed to be a slip-proof tile and it meets the coefficient of friction for ADA requirements but it’s still slippery when wet’ or someone will find that their installer accidentally put the wall tile on the floor.” Using Slip Guard is a way to salvage the situation rather than tear up the floor. It also, says Dorsett, “makes it possible to use a lot of tile in wet areas and entrances and pool decks where it normally couldn’t be used.”

Ahern firmly believes that Slip Tech and similar products need to be applied by qualified contractors. “You have to control the amount of etch,” he notes, “it’s not a matter of one bottle and one strength. What works well on one tile will destroy another one.” More importantly, notes Ahern, hydrofluoric acid is a strong chemical and a class A hazardous material. It can get on skin and not be felt until several hours later when it’s burning a hole down into the bone.

Slip Tech technicians always ask that a tile sample to be sent to them for analysis prior to treatment. For example, notes Ahern, it takes a different concentration of acid and a longer “dwell” time to take .2 tile to a .6 than it does to take a .5 to a .6. Floors that use a variety of tile with different coefficients of friction need to have those tiles individually treated for optimum performance.

Dorsett claims that his product doesn’t alter the appearance of the glaze or the aesthetics. ”When you treat it and the tile is dry and you run your hand over it, you can’t even tell. It’s as smooth as it was beforehand. It’s when it’s wet that it makes the difference.” Sometimes, notes Dorsett, slippery tile is specified for aesthetic reasons and then is treated afterwards.

If every floor were to be laid with tiles that were manufactured to be slip resistant, it would seem as if companies like Slip Tech and Slip Guard would quickly be out of business. “In reality,” claims Ahern, “there are very, very few tiles that meet the .6 coefficient of friction….Manufacturers find it very, very difficult, almost impossible, to make a pretty .6 tile. You can make what I call prison tile, real rough stuff, that if you fell on it you’d bleed, but very few tiles that you find attractive can be made at .6 in the factory, which is how this [deglazing] industry got going.”

Ahern notes Slip Tech has been used by a number of different entities ranging from banks and casinos to 7-11s and McDonald’s. All of them were anxious to avoid slip and fall lawsuits, so Ahern feels that the $3 per square foot it costs to treat tile is money well spent. He is so confident of Slip Tech’s anti-slip properties that he once had kids play basketball on a sopping wet treated tile floor to demonstrate the product’s effectiveness before representatives from the Hilton Hotels chain.

To view ADAAG’s technical bulletin on ground and floor surfaces please visit:

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