Technical Bulletin: Ground and Floor Surfaces

In new construction and alterations, surface materials must be specified to be slip-resistant. If there is a choice between flooring materials otherwise suitable for a particular application, we recommend choosing the material with the higher coefficient of friction, particularly for ramps.

Materials that might be appropriate for ramps and level surfaces include concrete wood float surfaces, asphalt, and some types of carpets and resilient tiles. Materials which might be expected to be satisfactory for level surfaces, but which might not be appropriate for ramps, include concrete metal trowelled surfaces, ceramic tile, hardwood and flagstone. These finishes, tested during the Access Board research project, yielded coefficients of friction that fell within the recommended ranges for accessible routes.

However, not all products of the type mentioned may provide the desired slip resistance and many other materials can be expected to be suitable even though they are not included here. For example, some types of materials for which the coefficient of friction is low, are available--or can be treated--with finishes that increase slip resistance.

Products or finishes applied to surfaces after installation are not covered by ADAAG. but may fall under the Department of Justice (DOJ) regulation governing the maintenance of accessible features. Moisture and debris contamination adversely affect the surface slip resistance of most installed finishes. While floor treatments are available that will increase the coefficient of friction of a walking surface, some products or furnishings, such as furniture wax overspray or loose throw rugs, may reduce slip resistance significantly. Others-- for example, walkoff mats placed on lobby floors during rainy weather-- do much to reduce the chance of slipping on a wet floor. Such mats are not considered carpets within the meaning of ADAAG 4.5.3.