A key consideration in the design of accessible play areas is the type of surfacing to use. It is important that play surface materials be suitable for cushioning falls, yet firm and stable enough to provide access for persons with disabilities. Surfacing is addressed by guidelines for play areas the Board developed under the Americans with Disabilities Act which reference standards developed by the American Society for Testing and Materials (ASTM) for impact attenuation and wheelchair maneuverability. The Board has sponsored research on the suitability of engineered wood fiber, a popular surfacing material, and various binding agents that can enhance its usability. A report is now available on the results of field testing completed last fall by the U.S. Forest Service’s Forest Products Laboratory in Madison, Wisconsin.
In a preliminary phase, researchers analyzed various surface treatments on different types of engineered wood fiber. Based on this analysis, different test configurations were selected for field evaluations and performance testing. The study tested various types of binders (latex, silicone, and polyurethane) that can enhance surface firmness and stability of engineered wood fiber. The study included seven surface treatments and one untreated control surface installed in a series of outdoor test beds which were evaluated over a six-month period. Researchers exposed the surfaces to a wide range of climatic conditions, including freeze-thaw cycles, rain, and heat.
Periodic tests of surface firmness and stability were performed to assess durability and performance loss before and after field exposure. At the end of the test period, impact tests were conducted according to ASTM protocols. Durability and moisture levels were also evaluated. All surface treatments of the study passed ASTM specifications for impact attenuation, and some (silicone and latex) had levels similar to the untreated material. The polyurethane binder scored higher on firmness and stability than the other treatments and the untreated material. The study also found that the surface treatments caused the underlying wood material to retain moisture, which may necessitate further study on this effect. The results are summarized in a report, “Improved Engineered Wood Fiber Surfaces for Accessible Playgrounds,” which is available from the Board. Follow-up testing is to be conducted this spring to measure 12-month field exposure.
A third phase is planned which will further assess those treatments that ranked highest in the completed study (polyurethane and latex). This next phase will involve a full-scale field assessment of these surface stabilizers at a playground. The Board is seeking good candidates for site testing where the Forest Products Laboratory can install the surfaces to be tested, assess their performance, and receive user reactions. For further information, contact Bill Botten of the Board at (202) 272-0014 (v), (202) 272-0082 (TTY), or email@example.com (e-mail).